WorldWideScience

Sample records for optoelectronic devices

  1. Deformable paper origami optoelectronic devices

    KAUST Repository

    He, Jr-Hau

    2017-01-19

    Deformable optoelectronic devices are provided, including photodetectors, photodiodes, and photovoltaic cells. The devices can be made on a variety of paper substrates, and can include a plurality of fold segments in the paper substrate creating a deformable pattern. Thin electrode layers and semiconductor nanowire layers can be attached to the substrate, creating the optoelectronic device. The devices can be highly deformable, e.g. capable of undergoing strains of 500% or more, bending angles of 25° or more, and/or twist angles of 270° or more. Methods of making the deformable optoelectronic devices and methods of using, e.g. as a photodetector, are also provided.

  2. Deformable paper origami optoelectronic devices

    KAUST Repository

    He, Jr-Hau; Lin, Chun-Ho

    2017-01-01

    Deformable optoelectronic devices are provided, including photodetectors, photodiodes, and photovoltaic cells. The devices can be made on a variety of paper substrates, and can include a plurality of fold segments in the paper substrate creating a

  3. Radiation effects in optoelectronic devices

    International Nuclear Information System (INIS)

    Barnes, C.E.; Wiczer, J.J.

    1984-05-01

    Purpose of this report is to provide not only a summary of radiation damage studies at Sandia National Laboratories, but also of those in the literature on the components of optoelectronic systems: light emitting diodes (LEDs), laser diodes, photodetectors, optical fibers, and optical isolators. This review of radiation damage in optoelectronic components is structured according to device type. In each section, a brief discussion of those device properties relevant to radiation effects is given

  4. Organic 'Plastic' Optoelectronic Devices

    International Nuclear Information System (INIS)

    Sariciftci, N.S.

    2006-01-01

    Recent developments on conjugated polymer based photovoltaic diodes and photoactive organic field effect transistors (photOFETs) are discussed. The photophysics of such devices is based on the photoinduced charge transfer from donor type semiconducting conjugated polymers onto acceptor type conjugated polymers or acceptor molecules such as Buckminsterfullerene, C 6 0. Potentially interesting applications include sensitization of the photoconductivity and photovoltaic phenomena as well as photoresponsive organic field effect transistors (photOFETs). Furthermore, organic polymeric/inorganic nanoparticle based 'hybrid' solar cells will be discussed. This talk gives an overview of materials' aspect, charge-transport, and device physics of organic diodes and field-effect transistors. Furthermore, due to the compatibility of carbon/hydrogen based organic semiconductors with organic biomolecules and living cells there can be a great opportunity to integrate such organic semiconductor devices (biOFETs) with the living organisms. In general the largely independent bio/lifesciences and information technology of today, can be thus bridged in an advanced cybernetic approach using organic semiconductor devices embedded in bio-lifesciences. This field of bio-organic electronic devices is proposed to be an important mission of organic semiconductor devices

  5. Organic optoelectronics:materials,devices and applications

    Institute of Scientific and Technical Information of China (English)

    LIU Yi; CUI Tian-hong

    2005-01-01

    The interest in organic materials for optoelectronic devices has been growing rapidly in the last two decades. This growth has been propelled by the exciting advances in organic thin films for displays, low-cost electronic circuits, etc. An increasing number of products employing organic electronic devices have become commercialized, which has stimulated the age of organic optoelectronics. This paper reviews the recent progress in organic optoelectronic technology. First, organic light emitting electroluminescent materials are introduced. Next, the three kinds of most important organic optoelectronic devices are summarized, including light emitting diode, organic photovoltaic cell, and photodetectors. The various applications of these devices are also reviewed and discussed in detail. Finally, the market and future development of optoelectronic devices are also demonstrated.

  6. Metamaterial mirrors in optoelectronic devices

    KAUST Repository

    Esfandyarpour, Majid

    2014-06-22

    The phase reversal that occurs when light is reflected from a metallic mirror produces a standing wave with reduced intensity near the reflective surface. This effect is highly undesirable in optoelectronic devices that use metal films as both electrical contacts and optical mirrors, because it dictates a minimum spacing between the metal and the underlying active semiconductor layers, therefore posing a fundamental limit to the overall thickness of the device. Here, we show that this challenge can be circumvented by using a metamaterial mirror whose reflection phase is tunable from that of a perfect electric mirror († = €) to that of a perfect magnetic mirror († = 0). This tunability in reflection phase can also be exploited to optimize the standing wave profile in planar devices to maximize light-matter interaction. Specifically, we show that light absorption and photocurrent generation in a sub-100 nm active semiconductor layer of a model solar cell can be enhanced by ∼20% over a broad spectral band. © 2014 Macmillan Publishers Limited.

  7. Metamaterial mirrors in optoelectronic devices

    KAUST Repository

    Esfandyarpour, Majid; Garnett, Erik C.; Cui, Yi; McGehee, Michael D.; Brongersma, Mark L.

    2014-01-01

    The phase reversal that occurs when light is reflected from a metallic mirror produces a standing wave with reduced intensity near the reflective surface. This effect is highly undesirable in optoelectronic devices that use metal films as both electrical contacts and optical mirrors, because it dictates a minimum spacing between the metal and the underlying active semiconductor layers, therefore posing a fundamental limit to the overall thickness of the device. Here, we show that this challenge can be circumvented by using a metamaterial mirror whose reflection phase is tunable from that of a perfect electric mirror († = €) to that of a perfect magnetic mirror († = 0). This tunability in reflection phase can also be exploited to optimize the standing wave profile in planar devices to maximize light-matter interaction. Specifically, we show that light absorption and photocurrent generation in a sub-100 nm active semiconductor layer of a model solar cell can be enhanced by ∼20% over a broad spectral band. © 2014 Macmillan Publishers Limited.

  8. Optoelectronic Devices Advanced Simulation and Analysis

    CERN Document Server

    Piprek, Joachim

    2005-01-01

    Optoelectronic devices transform electrical signals into optical signals and vice versa by utilizing the sophisticated interaction of electrons and light within micro- and nano-scale semiconductor structures. Advanced software tools for design and analysis of such devices have been developed in recent years. However, the large variety of materials, devices, physical mechanisms, and modeling approaches often makes it difficult to select appropriate theoretical models or software packages. This book presents a review of devices and advanced simulation approaches written by leading researchers and software developers. It is intended for scientists and device engineers in optoelectronics, who are interested in using advanced software tools. Each chapter includes the theoretical background as well as practical simulation results that help to better understand internal device physics. The software packages used in the book are available to the public, on a commercial or noncommercial basis, so that the interested r...

  9. Radiation effects in optoelectronic devices

    International Nuclear Information System (INIS)

    Barnes, C.E.

    1977-03-01

    A summary is given of studies on radiation effects in light-emitting diodes, laser diodes, detectors, optical isolators and optical fibers. It is shown that the study of radiation damage in these devices can provide valuable information concerning the nature of the devices themselves, as well as methods of hardening these devices for applications in radiation environments

  10. New Development of Membrane Base Optoelectronic Devices

    Directory of Open Access Journals (Sweden)

    Leon Hamui

    2017-12-01

    Full Text Available It is known that one factor that affects the operation of optoelectronic devices is the effective protection of the semiconductor materials against environmental conditions. The permeation of atmospheric oxygen and water molecules into the device structure induces degradation of the electrodes and the semiconductor. As a result, in this communication we report the fabrication of semiconductor membranes consisting of Magnesium Phthalocyanine-allene (MgPc-allene particles dispersed in Nylon 11 films. These membranes combine polymer properties with organic semiconductors properties and also provide a barrier effect for the atmospheric gas molecules. They were prepared by high vacuum evaporation and followed by thermal relaxation technique. For the characterization of the obtained membranes, Fourier-transform infrared spectroscopy (FT-IR, scanning electron microscopy (SEM, and energy dispersive spectroscopy (EDS were used to determine the chemical and microstructural properties. UV-ViS, null ellipsometry, and visible photoluminescence (PL at room temperature were used to characterize the optoelectronic properties. These results were compared with those obtained for the organic semiconductors: MgPc-allene thin films. Additionally, semiconductor membranes devices have been prepared, and a study of the device electronic transport properties was conducted by measuring electrical current density-voltage (J-V characteristics by four point probes with different wavelengths. The resistance properties against different environmental molecules are enhanced, maintaining their semiconductor functionality that makes them candidates for optoelectronic applications.

  11. Organic Optoelectronic Devices Employing Small Molecules

    Science.gov (United States)

    Fleetham, Tyler Blain

    Organic optoelectronic devices have remained a research topic of great interest over the past two decades, particularly in the development of efficient organic photovoltaics (OPV) and organic light emitting diodes (OLED). In order to improve the efficiency, stability, and materials variety for organic optoelectronic devices a number of emitting materials, absorbing materials, and charge transport materials were developed and employed in a device setting. Optical, electrical, and photophysical studies of the organic materials and their corresponding devices were thoroughly carried out. Two major approaches were taken to enhance the efficiency of small molecule based OPVs: developing material with higher open circuit voltages or improved device structures which increased short circuit current. To explore the factors affecting the open circuit voltage (VOC) in OPVs, molecular structures were modified to bring VOC closer to the effective bandgap, DeltaE DA, which allowed the achievement of 1V VOC for a heterojunction of a select Ir complex with estimated exciton energy of only 1.55eV. Furthermore, the development of anode interfacial layer for exciton blocking and molecular templating provide a general approach for enhancing the short circuit current. Ultimately, a 5.8% PCE was achieved in a single heterojunction of C60 and a ZnPc material prepared in a simple, one step, solvent free, synthesis. OLEDs employing newly developed deep blue emitters based on cyclometalated complexes were demonstrated. Ultimately, a peak EQE of 24.8% and nearly perfect blue emission of (0.148,0.079) was achieved from PtON7dtb, which approaches the maximum attainable performance from a blue OLED. Furthermore, utilizing the excimer formation properties of square-planar Pt complexes, highly efficient and stable white devices employing a single emissive material were demonstrated. A peak EQE of over 20% for pure white color (0.33,0.33) and 80 CRI was achieved with the tridentate Pt complex, Pt

  12. Hybrid optoelectronic device with multiple bistable outputs

    Energy Technology Data Exchange (ETDEWEB)

    Costazo-Caso, Pablo A; Jin Yiye; Gelh, Michael; Granieri, Sergio; Siahmakoun, Azad, E-mail: pcostanzo@ing.unlp.edu.are, E-mail: granieri@rose-hulma.edu, E-mail: siahmako@rose-hulma.edu [Department of Physics and Optical Engineering, Rose-Hulman Institute of Technology, 5500 Wabash Avenue, Terre Haute, IN 47803 (United States)

    2011-01-01

    Optoelectronic circuits which exhibit optical and electrical bistability with hysteresis behavior are proposed and experimentally demonstrated. The systems are based on semiconductor optical amplifiers (SOA), bipolar junction transistors (BJT), PIN photodiodes (PD) and laser diodes externally modulated with integrated electro-absorption modulators (LD-EAM). The device operates based on two independent phenomena leading to both electrical bistability and optical bistability. The electrical bistability is due to the series connection of two p-i-n structures (SOA, BJT, PD or LD) in reverse bias. The optical bistability is consequence of the quantum confined Stark effect (QCSE) in the multi-quantum well (MQW) structure in the intrinsic region of the device. This effect produces the optical modulation of the transmitted light through the SOA (or reflected from the PD). Finally, because the optical transmission of the SOA (in reverse bias) and the reflected light from the PD are so small, a LD-EAM modulated by the voltage across these devices are employed to obtain a higher output optical power. Experiments show that the maximum switching frequency is in MHz range and the rise/fall times lower than 1 us. The temporal response is mainly limited by the electrical capacitance of the devices and the parasitic inductances of the connecting wires. The effects of these components can be reduced in current integration technologies.

  13. Ultrafast characterization of optoelectronic devices and systems

    Science.gov (United States)

    Zheng, Xuemei

    The recent fast growth in high-speed electronics and optoelectronics has placed demanding requirements on testing tools. Electro-optic (EO) sampling is a well-established technique for characterization of high-speed electronic and optoelectronic devices and circuits. However, with the progress in device miniaturization, lower power consumption (smaller signal), and higher throughput (higher clock rate), EO sampling also needs to be updated, accordingly, towards better signal-to-noise ratio (SNR) and sensitivity, without speed sacrifice. In this thesis, a novel EO sampler with a single-crystal organic 4-dimethylamino-N-methy-4-stilbazolium tosylate (DAST) as the EO sensor is developed. The system exhibits sub-picosecond temporal resolution, sub-millivolt sensitivity, and a 10-fold improvement on SNR, compared with its LiTaO3 counterpart. The success is attributed to the very high EO coefficient, the very low dielectric constant, and the fast response, coming from the major contribution of the pi-electrons in DAST. With the advance of ultrafast laser technology, low-noise and compact femtosecond fiber lasers have come to maturation and become light-source options for ultrafast metrology systems. We have successfully integrated a femtosecond erbium-doped-fiber laser into an EO sampler, making the system compact and very reliable. The fact that EO sampling is essentially an impulse-response measurement process, requires integration of ultrashort (sub-picosecond) impulse generation network with the device under test. We have implemented a reliable lift-off and transfer technique in order to obtain epitaxial-quality freestanding low-temperature-grown GaAs (LT-GaAs) thin-film photo-switches, which can be integrated with many substrates. The photoresponse of our freestanding LT-GaAs devices was thoroughly characterized with the help of our EO sampler. As fast as 360 fs full-width-at-half-maximum (FWHM) and >1 V electrical pulses were obtained, with quantum efficiency

  14. Lasers and optoelectronics fundamentals, devices and applications

    CERN Document Server

    Maini, Anil K

    2013-01-01

    With emphasis on the physical and engineering principles, this book provides a comprehensive and highly accessible treatment of modern lasers and optoelectronics. Divided into four parts, it explains laser fundamentals, types of lasers, laser electronics & optoelectronics, and laser applications, covering each of the topics in their entirety, from basic fundamentals to advanced concepts. Key features include: exploration of technological and application-related aspects of lasers and optoelectronics, detailing both existing and emerging applications in industry, medical diag

  15. Introduction to organic electronic and optoelectronic materials and devices

    CERN Document Server

    Sun, Sam-Shajing

    2008-01-01

    Introduction to Optoelectronic Materials, N. Peyghambarian and M. Fallahi Introduction to Optoelectronic Device Principles, J. Piprek Basic Electronic Structures and Charge Carrier Generation in Organic Optoelectronic Materials, S.-S. Sun Charge Transport in Conducting Polymers, V.N. Prigodin and A.J. Epstein Major Classes of Organic Small Molecules for Electronic and Optoelectronics, X. Meng, W. Zhu, and H. Tian Major Classes of Conjugated Polymers and Synthetic Strategies, Y. Li and J. Hou Low Energy Gap, Conducting, and Transparent Polymers, A. Kumar, Y. Ner, and G.A. Sotzing Conjugated Polymers, Fullerene C60, and Carbon Nanotubes for Optoelectronic Devices, L. Qu, L. Dai, and S.-S. Sun Introduction of Organic Superconducting Materials, H. Mori Molecular Semiconductors for Organic Field-Effect Transistors, A. Facchetti Polymer Field-Effect Transistors, H.G.O. Sandberg Organic Molecular Light-Emitting Materials and Devices, F. So and J. Shi Polymer Light-Emitting Diodes: Devices and Materials, X. Gong and ...

  16. Quantum dot optoelectronic devices: lasers, photodetectors and solar cells

    International Nuclear Information System (INIS)

    Wu, Jiang; Chen, Siming; Seeds, Alwyn; Liu, Huiyun

    2015-01-01

    Nanometre-scale semiconductor devices have been envisioned as next-generation technologies with high integration and functionality. Quantum dots, or the so-called ‘artificial atoms’, exhibit unique properties due to their quantum confinement in all 3D. These unique properties have brought to light the great potential of quantum dots in optoelectronic applications. Numerous efforts worldwide have been devoted to these promising nanomaterials for next-generation optoelectronic devices, such as lasers, photodetectors, amplifiers, and solar cells, with the emphasis on improving performance and functionality. Through the development in optoelectronic devices based on quantum dots over the last two decades, quantum dot devices with exceptional performance surpassing previous devices are evidenced. This review describes recent developments in quantum dot optoelectronic devices over the last few years. The paper will highlight the major progress made in 1.3 μm quantum dot lasers, quantum dot infrared photodetectors, and quantum dot solar cells. (topical review)

  17. Optoelectronic device with nanoparticle embedded hole injection/transport layer

    Science.gov (United States)

    Wang, Qingwu [Chelmsford, MA; Li, Wenguang [Andover, MA; Jiang, Hua [Methuen, MA

    2012-01-03

    An optoelectronic device is disclosed that can function as an emitter of optical radiation, such as a light-emitting diode (LED), or as a photovoltaic (PV) device that can be used to convert optical radiation into electrical current, such as a photovoltaic solar cell. The optoelectronic device comprises an anode, a hole injection/transport layer, an active layer, and a cathode, where the hole injection/transport layer includes transparent conductive nanoparticles in a hole transport material.

  18. A simple encapsulation method for organic optoelectronic devices

    International Nuclear Information System (INIS)

    Sun Qian-Qian; An Qiao-Shi; Zhang Fu-Jun

    2014-01-01

    The performances of organic optoelectronic devices, such as organic light emitting diodes and polymer solar cells, have rapidly improved in the past decade. The stability of an organic optoelectronic device has become a key problem for further development. In this paper, we report one simple encapsulation method for organic optoelectronic devices with a parafilm, based on ternary polymer solar cells (PSCs). The power conversion efficiencies (PCE) of PSCs with and without encapsulation decrease from 2.93% to 2.17% and from 2.87% to 1.16% after 168-hours of degradation under an ambient environment, respectively. The stability of PSCs could be enhanced by encapsulation with a parafilm. The encapsulation method is a competitive choice for organic optoelectronic devices, owing to its low cost and compatibility with flexible devices. (atomic and molecular physics)

  19. Opto-electronic devices from block copolymers and their oligomers.

    NARCIS (Netherlands)

    Hadziioannou, G

    1997-01-01

    This paper presents research activities towards the development of polymer materials and devices for optoelectronics, An approach to controlling the conjugation length and transferring the luminescence properties of organic molecules to polymers through black copolymers containing well-defined

  20. Materials for optoelectronic devices, OEICs and photonics

    International Nuclear Information System (INIS)

    Schloetterer, H.; Quillec, M.; Greene, P.D.; Bertolotti, M.

    1991-01-01

    The aim of the contributors in this volume is to give a current overview on the basic properties of nonlinear optical materials for optoelectronics and integrated optics. They provide a cross-linkage between different materials (III-V, II-VI, Si-Ge, etc.), various sample dimensions (from bulk crystals to quantum dots), and a range of techniques from growth (LPE to MOMBE) and for processing from surface passivation to ion beams. Major growth techniques and materials are discussed, including the sophisticated technologies required to exploit the exciting properties of low dimensional semiconductors. These proceedings will prove an invaluable guide to the current state of optoelectronic materials development, as well as indicating the growth techniques that will be in use around the year 2000

  1. Flexible and Stretchable Optoelectronic Devices using Silver Nanowires and Graphene.

    Science.gov (United States)

    Lee, Hanleem; Kim, Meeree; Kim, Ikjoon; Lee, Hyoyoung

    2016-06-01

    Many studies have accompanied the emergence of a great interest in flexible or/and stretchable devices for new applications in wearable and futuristic technology, including human-interface devices, robotic skin, and biometric devices, and in optoelectronic devices. Especially, new nanodimensional materials enable flexibility or stretchability to be brought based on their dimensionality. Here, the emerging field of flexible devices is briefly introduced using silver nanowires and graphene, which are famous nanomaterials for the use of transparent conductive electrodes, as examples, and their unique functions originating from the intrinsic property of these nanomaterials are highlighted. It is thought that this work will evoke more interest and idea exchanges in this emerging field and hopefully can trigger a breakthrough on a new type of optoelectronics and optogenetic devices in the near future. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Recent advances in flexible and wearable organic optoelectronic devices

    Science.gov (United States)

    Zhu, Hong; Shen, Yang; Li, Yanqing; Tang, Jianxin

    2018-01-01

    Flexible and wearable optoelectronic devices have been developing to a new stage due to their unique capacity for the possibility of a variety of wearable intelligent electronics, including bendable smartphones, foldable touch screens and antennas, paper-like displays, and curved and flexible solid-state lighting devices. Before extensive commercial applications, some issues still have to be solved for flexible and wearable optoelectronic devices. In this regard, this review concludes the newly emerging flexible substrate materials, transparent conductive electrodes, device architectures and light manipulation methods. Examples of these components applied for various kinds of devices are also summarized. Finally, perspectives about the bright future of flexible and wearable electronic devices are proposed. Project supported by the Ministry of Science and Technology of China (No. 2016YFB0400700).

  3. Dental impression technique using optoelectronic devices

    Science.gov (United States)

    Sinescu, Cosmin; Barua, Souman; Topala, Florin Ionel; Negrutiu, Meda Lavinia; Duma, Virgil-Florin; Gabor, Alin Gabriel; Zaharia, Cristian; Bradu, Adrian; Podoleanu, Adrian G.

    2018-03-01

    INTRODUCTION: The use of Optical Coherence Tomography (OCT) as a non-invasive and high precision quantitative information providing tool has been well established by researches within the last decade. The marginal discrepancy values can be scrutinized in optical biopsy made in three dimensional (3D) micro millimetre scale and reveal detailed qualitative and quantitative information of soft and hard tissues. OCT-based high resolution 3D images can provide a significant impact on finding recurrent caries, restorative failure, analysing the precision of crown preparation, and prosthetic elements marginal adaptation error with the gingiva and dental hard tissues. During the CAD/CAM process of prosthodontic restorations, the circumvent of any error is important for the practitioner and the technician to reduce waste of time and material. Additionally, OCT images help to achieve a new or semi-skilled practitioner to analyse their crown preparation works and help to develop their skills faster than in a conventional way. The aim of this study is to highlight the advantages of OCT in high precision prosthodontic restorations. MATERIALS AND METHODS: 25 preparations of frontal and lateral teeth were performed for 7 different patients. The impressions of the prosthetic fields were obtained both using a conventional optoelectronic system (Apolo Di, Syrona) and a Spectral Domain using OCT (Dental prototype, working at 860 nm). For the conventional impression technique the preparation margins were been prelevated by gingival impregnated cords. No specific treatments were performed by the OCT impression technique. RESULTS: The scanning performed by conventional optoelectronic system proved to be quick and accurate in terms of impression technology. The results were represented by 3D virtual models obtained after the scanning procedure was completed. In order to obtain a good optical impression a gingival retraction cord was inserted between the prepared tooth and the gingival

  4. Optoelectronic devices product assurance guideline for space application

    Science.gov (United States)

    Bensoussan, A.; Vanzi, M.

    2017-11-01

    New opportunities are emerging for the implementation of hardware sub-systems based on OptoElectronic Devices (OED) for space application. Since the end of this decade the main players for space systems namely designers and users including Industries, Agencies, Manufacturers and Laboratories are strongly demanding of adequate strategies to qualify and validate new optoelectronics products and sub-systems [1]. The long term space application mission will require to address either inter-satellite link (free space communication, positioning systems, tracking) or intra-satellite connectivity/flexibility/reconfigurability or high volume of data transfer between equipment installed into payload.

  5. 77 FR 65713 - Certain Optoelectronic Devices for Fiber Optic Communications, Components Thereof, and Products...

    Science.gov (United States)

    2012-10-30

    ... Fiber Optic Communications, Components Thereof, and Products Containing the Same; Notice of Institution... certain optoelectronic devices for fiber optic communications, components thereof, and products containing... optoelectronic devices for fiber optic communications, components thereof, and products containing the same that...

  6. CuPc/C60 heterojunction thin film optoelectronic devices

    International Nuclear Information System (INIS)

    Murtaza, Imran; Karimov, Khasan S.; Qazi, Ibrahim

    2010-01-01

    The optoelectronic properties of heterojunction thin film devices with ITO/CuPc/C 60 /Al structure have been investigated by analyzing their current-voltage characteristics, optical absorption and photocurrent. In this organic photovoltaic device, CuPc acts as an optically active layer, C 60 as an electron-transporting layer and ITO and Al as electrodes. It is observed that, under illumination, excitons are formed, which subsequently drift towards the interface with C 60 , where an internal electric field is present. The excitons that reach the interface are subsequently dissociated into free charge carriers due to the electric field present at the interface. The experimental results show that in this device the total current density is a function of injected carriers at the electrode-organic semiconductor surface, the leakage current through the organic layer and collected photogenerated current that results from the effective dissociation of excitons. (semiconductor devices)

  7. Optical Near-field Interactions and Forces for Optoelectronic Devices

    Science.gov (United States)

    Kohoutek, John Michael

    Throughout history, as a particle view of the universe began to take shape, scientists began to realize that these particles were attracted to each other and hence came up with theories, both analytical and empirical in nature, to explain their interaction. The interaction pair potential (empirical) and electromagnetics (analytical) theories, both help to explain not only the interaction between the basic constituents of matter, such as atoms and molecules, but also between macroscopic objects, such as two surfaces in close proximity. The electrostatic force, optical force, and Casimir force can be categorized as such forces. A surface plasmon (SP) is a collective motion of electrons generated by light at the interface between two mediums of opposite signs of dielectric susceptibility (e.g. metal and dielectric). Recently, surface plasmon resonance (SPR) has been exploited in many areas through the use of tiny antennas that work on similar principles as radio frequency (RF) antennas in optoelectronic devices. These antennas can produce a very high gradient in the electric field thereby leading to an optical force, similar in concept to the surface forces discussed above. The Atomic Force Microscope (AFM) was introduced in the 1980s at IBM. Here we report on its uses in measuring these aforementioned forces and fields, as well as actively modulating and manipulating multiple optoelectronic devices. We have shown that it is possible to change the far field radiation pattern of an optical antenna-integrated device through modification of the near-field of the device. This modification is possible through change of the local refractive index or reflectivity of the "hot spot" of the device, either mechanically or optically. Finally, we have shown how a mechanically active device can be used to detect light with high gain and low noise at room temperature. It is the aim of several of these integrated and future devices to be used for applications in molecular sensing

  8. Wonder of nanotechnology quantum optoelectronic devices and applications

    CERN Document Server

    Razeghi, Manijeh; von Klitzing, Klaus

    2013-01-01

    When you look closely, Nature is nanotechnology at its finest. From a single cell, a factory all by itself, to complex systems, such as the nervous system or the human eye, each is composed of specialized nanostructures that exist to perform a specific function. This same beauty can be mirrored when we interact with the tiny physical world that is the realm of quantum mechanics.The Wonder of Nanotechnology: Quantum Optoelectronic Devices and Applications, edited by Manijeh Razeghi, Leo Esaki, and Klaus von Klitzing focuses on the application of nanotechnology to modern semiconductor optoelectr

  9. Growing perovskite into polymers for easy-processable optoelectronic devices

    Science.gov (United States)

    Masi, Sofia; Colella, Silvia; Listorti, Andrea; Roiati, Vittoria; Liscio, Andrea; Palermo, Vincenzo; Rizzo, Aurora; Gigli, Giuseppe

    2015-01-01

    Here we conceive an innovative nanocomposite to endow hybrid perovskites with the easy processability of polymers, providing a tool to control film quality and material crystallinity. We verify that the employed semiconducting polymer, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), controls the self-assembly of CH3NH3PbI3 (MAPbI3) crystalline domains and favors the deposition of a very smooth and homogenous layer in one straightforward step. This idea offers a new paradigm for the implementation of polymer/perovskite nanocomposites towards versatile optoelectronic devices combined with the feasibility of mass production. As a proof-of-concept we propose the application of such nanocomposite in polymer solar cell architecture, demonstrating a power conversion efficiency up to 3%, to date the highest reported for MEH-PPV. On-purpose designed polymers are expected to suit the nanocomposite properties for the integration in diverse optoelectronic devices via facile processing condition.

  10. Photon management of GaN-based optoelectronic devices via nanoscaled phenomena

    KAUST Repository

    Tsai, Yu-Lin; Lai, Kun-Yu; Lee, Ming-Jui; Liao, Yu-Kuang; Ooi, Boon S.; Kuo, Hao-Chung; He, Jr-Hau

    2016-01-01

    Photon management is essential in improving the performances of optoelectronic devices including light emitting diodes, solar cells and photo detectors. Beyond the advances in material growth and device structure design, photon management via

  11. Optoelectronic devices, low temperature preparation methods, and improved electron transport layers

    KAUST Repository

    Eita, Mohamed S.; El, Labban Abdulrahman; Usman, Anwar; Beaujuge, Pierre; Mohammed, Omar F.

    2016-01-01

    An optoelectronic device such as a photovoltaic device which has at least one layer, such as an electron transport layer, which comprises a plurality of alternating, oppositely charged layers including metal oxide layers. The metal oxide can be zinc

  12. Electronic and optoelectronic materials and devices inspired by nature

    Science.gov (United States)

    Meredith, P.; Bettinger, C. J.; Irimia-Vladu, M.; Mostert, A. B.; Schwenn, P. E.

    2013-03-01

    Inorganic semiconductors permeate virtually every sphere of modern human existence. Micro-fabricated memory elements, processors, sensors, circuit elements, lasers, displays, detectors, etc are ubiquitous. However, the dawn of the 21st century has brought with it immense new challenges, and indeed opportunities—some of which require a paradigm shift in the way we think about resource use and disposal, which in turn directly impacts our ongoing relationship with inorganic semiconductors such as silicon and gallium arsenide. Furthermore, advances in fields such as nano-medicine and bioelectronics, and the impending revolution of the ‘ubiquitous sensor network’, all require new functional materials which are bio-compatible, cheap, have minimal embedded manufacturing energy plus extremely low power consumption, and are mechanically robust and flexible for integration with tissues, building structures, fabrics and all manner of hosts. In this short review article we summarize current progress in creating materials with such properties. We focus primarily on organic and bio-organic electronic and optoelectronic systems derived from or inspired by nature, and outline the complex charge transport and photo-physics which control their behaviour. We also introduce the concept of electrical devices based upon ion or proton flow (‘ionics and protonics’) and focus particularly on their role as a signal interface with biological systems. Finally, we highlight recent advances in creating working devices, some of which have bio-inspired architectures, and summarize the current issues, challenges and potential solutions. This is a rich new playground for the modern materials physicist.

  13. Light Management in Optoelectronic Devices with Disordered and Chaotic Structures

    KAUST Repository

    Khan, Yasser

    2012-07-01

    With experimental realization, energy harvesting capabilities of chaotic microstructures were explored. Incident photons falling into chaotic trajectories resulted in energy buildup for certain frequencies. As a consequence, many fold enhancement in light trapping was observed. These ellipsoid like chaotic microstructures demonstrated 25% enhancement in light trapping at 450nm excitation and 15% enhancement at 550nm excitation. Optimization of these structures can drive novel chaos-assisted energy harvesting systems. In subsequent sections of the thesis, prospect of broadband light extraction from white light emitting diodes were investigated, which is an unchallenged but quintessential problem in solid-state lighting. Size dependent scattering allows microstructures to interact strongly with narrow-band light. If disorder is introduced in spread and sizes of microstructures, broadband light extraction is possible. A novel scheme with Voronoi tessellation to quantify disorder in physical systems was also introduced, and a link between voronoi disorder and state disorder of statistical mechanics was established. Overall, in this thesis some nascent concepts regarding disorder and chaos were investigated to efficiently manage electromagnetic waves in optoelectronic devices.

  14. Electronic and optoelectronic materials and devices inspired by nature

    International Nuclear Information System (INIS)

    Meredith, P; Schwenn, P E; Bettinger, C J; Irimia-Vladu, M; Mostert, A B

    2013-01-01

    Inorganic semiconductors permeate virtually every sphere of modern human existence. Micro-fabricated memory elements, processors, sensors, circuit elements, lasers, displays, detectors, etc are ubiquitous. However, the dawn of the 21st century has brought with it immense new challenges, and indeed opportunities—some of which require a paradigm shift in the way we think about resource use and disposal, which in turn directly impacts our ongoing relationship with inorganic semiconductors such as silicon and gallium arsenide. Furthermore, advances in fields such as nano-medicine and bioelectronics, and the impending revolution of the ‘ubiquitous sensor network’, all require new functional materials which are bio-compatible, cheap, have minimal embedded manufacturing energy plus extremely low power consumption, and are mechanically robust and flexible for integration with tissues, building structures, fabrics and all manner of hosts. In this short review article we summarize current progress in creating materials with such properties. We focus primarily on organic and bio-organic electronic and optoelectronic systems derived from or inspired by nature, and outline the complex charge transport and photo-physics which control their behaviour. We also introduce the concept of electrical devices based upon ion or proton flow (‘ionics and protonics’) and focus particularly on their role as a signal interface with biological systems. Finally, we highlight recent advances in creating working devices, some of which have bio-inspired architectures, and summarize the current issues, challenges and potential solutions. This is a rich new playground for the modern materials physicist. (review article)

  15. Characterization of Semiconductor Nanocrystal Assemblies as Components of Optoelectronic Devices

    Science.gov (United States)

    Malfavon-Ochoa, Mario

    dispersions of core and core/shell NCs will be shown to produce close packed assemblies of NCs forming near-wavelength luminescent superstructures separated in space. We show the dominant contribution of a two-monolayer thick sharp interface CdS shell to the diffraction efficiency, and necessarily the refractive index, of the NCs, independent of core size. Utilization of these gratings as in-coupling elements at various positions within a device architecture are also examined. These new observations were achieved by unprecedented control of NC architecture during dispersion processing, while maintaining high luminescence, made possible by optimized NC surface passivation. These studies enable the formation of new LED architectures, and new optoelectronic devices based on angle resolved, monochromatic fluorescence from diffraction gratings prepared from simple solution processing approaches. Further, the novel observation of angle amplified interfering fluorescence from these features is argued to be a result of long range radiative coupling and superradiance enabled by the monodispersity and high-quality NC surface passivation described herein.

  16. Integrated graphene-based devices for optoelectronic applications

    DEFF Research Database (Denmark)

    Xiao, Sanshui

    Graphene opens up for novel optoelectronic applications thanks to its high carrier mobility, ultralarge absorption bandwidth, and extremely fast material response. Here I present novel integrated grapheneplasmonic waveguide modulator showing high modulation depth, thus giving a promising way...

  17. GaN nano-membrane for optoelectronic and electronic device applications

    KAUST Repository

    Ooi, Boon S.

    2014-01-01

    The ~25nm thick threading dislocation free GaN nanomembrane was prepared using ultraviolet electroless chemical etching method offering the possibility of flexible integration of (Al,In,Ga)N optoelectronic and electronic devices.

  18. 78 FR 16296 - Certain Optoelectronic Devices for Fiber Optic Communications, Components Thereof, and Products...

    Science.gov (United States)

    2013-03-14

    ... Fiber Optic Communications, Components Thereof, and Products Containing Same; Commission Determination... United States after importation of certain optoelectronic devices for fiber optic communications... Fiber IP (Singapore) Pte. Ltd. of Singapore (``Avago Fiber IP''); Avago General IP and Avago...

  19. Nanopatterned Metallic Films for Use As Transparent Conductive Electrodes in Optoelectronic Devices

    KAUST Repository

    Catrysse, Peter B.; Fan, Shanhui

    2010-01-01

    We investigate the use of nanopatterned metallic films as transparent conductive electrodes in optoelectronic devices. We find that the physics of nanopatterned electrodes, which are often optically thin metallic films, differs from

  20. Crystalline Molybdenum Oxide Thin-Films for Application as Interfacial Layers in Optoelectronic Devices

    DEFF Research Database (Denmark)

    Fernandes Cauduro, André Luis; dos Reis, Roberto; Chen, Gong

    2017-01-01

    The ability to control the interfacial properties in metal-oxide thin films through surface defect engineering is vital to fine-tune their optoelectronic properties and thus their integration in novel optoelectronic devices. This is exemplified in photovoltaic devices based on organic, inorganic...... or hybrid technologies, where precise control of the charge transport properties through the interfacial layer is highly important for improving device performance. In this work, we study the effects of in situ annealing in nearly stoichiometric MoOx (x ∼ 3.0) thin-films deposited by reactive sputtering. We...... with structural characterizations, this work addresses a novel method for tuning, and correlating, the optoelectronic properties and microstructure of device-relevant MoOx layers....

  1. Precision Controlled Carbon Materials for Next-Generation Optoelectronic and Photonic Devices

    Science.gov (United States)

    2018-01-08

    engineer next-generation carbon-based optoelectronic and photonic devices with superior performance and capabilities. These devices include carbon...electronics; (4) nanostructured graphene plasmonics; and (5) polymer-nanotube conjugate chemistry . (1) Semiconducting carbon nanotube-based...applications (In Preparation, 2018). (5) Polymer-nanotube conjugate chemistry Conjugated polymers can be exploited as agents for selectively wrapping and

  2. Optoelectronic sensor device for monitoring ethanol concentration in winemaking applications

    Science.gov (United States)

    Jiménez-Márquez, F.; Vázquez, J.; Úbeda, J.; Rodríguez-Rey, J.; Sánchez-Rojas, J. L.

    2015-05-01

    The supervision of key variables such as sugar, alcohol, released CO2 and microbiological evolution in fermenting grape must is of great importance in the winemaking industry. However, the fermentation kinetics is assessed by monitoring the evolution of the density as it varies during a fermentation, since density is an indicator of the total amount of sugars, ethanol and glycerol. Even so, supervising the fermentation process is an awkward and non-comprehensive task, especially in wine cellars where production rates are massive, and enologists usually measure the density of the extracted samples from each fermentation tank manually twice a day. This work aims at the design of a fast, low-cost, portable and reliable optoelectronic sensor for measuring ethanol concentration in fermenting grape must samples. Different sets of model solutions, which contain ethanol, fructose, glucose, glycerol dissolved in water and emulate the grape must composition at different stages of the fermentation, were prepared both for calibration and validation. The absorption characteristics of these model solutions were analyzed by a commercial spectrophotometer in the NIR region, in order to identify key wavelengths from which valuable information regarding the sample composition can be extracted. Finally, a customized optoelectronic prototype based on absorbance measurements at two wavelengths belonging to the NIR region was designed, fabricated and successfully tested. The system, whose optoelectronics is reduced after a thorough analysis to only two LED lamps and their corresponding paired photodiodes operating at 1.2 and 1.3 μm respectively, calculates the ethanol content by a multiple linear regression.

  3. 78 FR 77166 - Certain Optoelectronic Devices for Fiber Optic Communications, Components Thereof, and Products...

    Science.gov (United States)

    2013-12-20

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-860] Certain Optoelectronic Devices for Fiber Optic Communications, Components Thereof, and Products Containing the Same; Notice of Request for Statements on the Public Interest AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY...

  4. 3D TCAD Simulation for Semiconductor Processes, Devices and Optoelectronics

    CERN Document Server

    Li, Simon

    2012-01-01

    Technology computer-aided design, or TCAD, is critical to today’s semiconductor technology and anybody working in this industry needs to know something about TCAD.  This book is about how to use computer software to manufacture and test virtually semiconductor devices in 3D.  It brings to life the topic of semiconductor device physics, with a hands-on, tutorial approach that de-emphasizes abstract physics and equations and emphasizes real practice and extensive illustrations.  Coverage includes a comprehensive library of devices, representing the state of the art technology, such as SuperJunction LDMOS, GaN LED devices, etc. Provides a vivid, internal view of semiconductor devices, through 3D TCAD simulation; Includes comprehensive coverage of  TCAD simulations for both optic and electronic devices, from nano-scale to high-voltage high-power devices; Presents material in a hands-on, tutorial fashion so that industry practitioners will find maximum utility; Includes a comprehensive library of devices, re...

  5. Optoelectronic device for the measurement of the absolute linear position in the micrometric displacement range

    Science.gov (United States)

    Morlanes, Tomas; de la Pena, Jose L.; Sanchez-Brea, Luis M.; Alonso, Jose; Crespo, Daniel; Saez-Landete, Jose B.; Bernabeu, Eusebio

    2005-07-01

    In this work, an optoelectronic device that provides the absolute position of a measurement element with respect to a pattern scale upon switch-on is presented. That means that there is not a need to perform any kind of transversal displacement after the startup of the system. The optoelectronic device is based on the process of light propagation passing through a slit. A light source with a definite size guarantees the relation of distances between the different elements that constitute our system and allows getting a particular optical intensity profile that can be measured by an electronic post-processing device providing the absolute location of the system with a resolution of 1 micron. The accuracy of this measuring device is restricted to the same limitations of any incremental position optical encoder.

  6. Opto-electronic devices with nanoparticles and their assemblies

    Science.gov (United States)

    Nguyen, Chieu Van

    Nanotechnology is a fast growing field; engineering matters at the nano-meter scale. A key nanomaterial is nanoparticles (NPs). These sub-wavelength (background noise. The second device is based on a one-dimensional (1-D) self-directed self-assembly of Au NPs mediated by dielectric materials. Depending on the coverage density of the Au NPs assembly deposited on the device, electronic emission was observed at ultra-low bias of 40V, leading to low-power plasma generation in air at atmospheric pressure. Light emitted from the plasma is apparent to the naked eyes. Similarly, 1-D self-assembly of Au NPs mediated by iron oxide was fabricated and exhibits ferro-magnetic behavior. The multi-functional 1-D self-assembly of Au NPs has great potential in modern electronics such as solid state lighting, plasma-based nanoelectronics, and memory devices.

  7. A full-duplex working integrated optoelectronic device for optical interconnect

    Science.gov (United States)

    Liu, Kai; Fan, Huize; Huang, Yongqing; Duan, Xiaofeng; Wang, Qi; Ren, Xiaomin; Wei, Qi; Cai, Shiwei

    2018-05-01

    In this paper, a full-duplex working integrated optoelectronic device is proposed. It is constructed by integrating a vertical cavity surface emitting laser (VCSEL) unit above a resonant cavity enhanced photodetector (RCE-PD) unit. Analysis shows that, the VCSEL unit has a threshold current of 1 mA and a slop efficiency of 0.66 W/A at 849.7 nm, the RCE-PD unit obtains its maximal absorption quantum efficiency of 90.24% at 811 nm with a FWHM of 4 nm. Moreover, the two units of the proposed integrated device can work independently from each other. So that the proposed integrated optoelectronic device can work full-duplex. It can be applied for single fiber bidirectional optical interconnects system.

  8. Optical modeling based on mean free path calculations for quantum dot phosphors applied to optoelectronic devices.

    Science.gov (United States)

    Shin, Min-Ho; Kim, Hyo-Jun; Kim, Young-Joo

    2017-02-20

    We proposed an optical simulation model for the quantum dot (QD) nanophosphor based on the mean free path concept to understand precisely the optical performance of optoelectronic devices. A measurement methodology was also developed to get the desired optical characteristics such as the mean free path and absorption spectra for QD nanophosphors which are to be incorporated into the simulation. The simulation results for QD-based white LED and OLED displays show good agreement with the experimental values from the fabricated devices in terms of spectral power distribution, chromaticity coordinate, CCT, and CRI. The proposed simulation model and measurement methodology can be applied easily to the design of lots of optoelectronics devices using QD nanophosphors to obtain high efficiency and the desired color characteristics.

  9. Features of the piezo-phototronic effect on optoelectronic devices based on wurtzite semiconductor nanowires.

    Science.gov (United States)

    Yang, Qing; Wu, Yuanpeng; Liu, Ying; Pan, Caofeng; Wang, Zhong Lin

    2014-02-21

    The piezo-phototronic effect, a three way coupling effect of piezoelectric, semiconductor and photonic properties in non-central symmetric semiconductor materials, utilizing the piezo-potential as a "gate" voltage to tune the charge transport/generation/recombination and modulate the performance of optoelectronic devices, has formed a new field and attracted lots of interest recently. The mechanism was verified in various optoelectronic devices such as light emitting diodes (LEDs), photodetectors and solar cells etc. The fast development and dramatic increasing interest in the piezo-phototronic field not only demonstrate the way the piezo-phototronic effects work, but also indicate the strong need for further research in the physical mechanism and potential applications. Furthermore, it is important to distinguish the contribution of the piezo-phototronic effect from other factors induced by external strain such as piezoresistance, band shifting or contact area change, which also affect the carrier behaviour and device performance. In this perspective, we review our recent progress on piezo-phototronics and especially focus on pointing out the features of piezo-phototronic effect in four aspects: I-V characteristics; c-axis orientation; influence of illumination; and modulation of carrier behaviour. Finally we proposed several criteria for describing the contribution made by the piezo-phototronic effect to the performance of optoelectronic devices. This systematic analysis and comparison will not only help give an in-depth understanding of the piezo-phototronic effect, but also work as guide for the design of devices in related areas.

  10. Functionalization of Semiconductor Nanomaterials for Optoelectronic Devices And Components

    Science.gov (United States)

    2015-03-04

    pristine single and multiwalled carbon nanotubes as different stacking layers in bulk heterojunction solar cells,” M. Alam Khan, Michio Matsumura and M. O...Phys. Lett. 102, 051904 (2013). http://dx.doi.org/10.1063/1.4789908 13. “Synthesis of iron pyrite nanocrystals utilizing trioctylphosphine oxide ...O. Manasreh, IEEE Electron Device Letters (Submitted). 20. “Characteristics of p-ZnO/n-GaN heterojunction photodetector,” Abla Al-Zouhbi, N. S

  11. Photon management of GaN-based optoelectronic devices via nanoscaled phenomena

    KAUST Repository

    Tsai, Yu-Lin

    2016-09-06

    Photon management is essential in improving the performances of optoelectronic devices including light emitting diodes, solar cells and photo detectors. Beyond the advances in material growth and device structure design, photon management via nanoscaled phenomena have also been demonstrated as a promising way for further modifying/improving the device performance. The accomplishments achieved by photon management via nanoscaled phenomena include strain-induced polarization field management, crystal quality improvement, light extraction/harvesting enhancement, radiation pattern control, and spectrum management. In this review, we summarize recent development, challenges and underlying physics of photon management in GaN-based light emitting diodes and solar cells. (C) 2016 Elsevier Ltd. All rights reserved.

  12. Advanced light emitting device structures for optoelectronic applications

    International Nuclear Information System (INIS)

    Kovac, J.

    2002-01-01

    Several factors are driving the recent development of light emitting devices (LED,s). The most important ones are brightness, available efficiency, architecture form flexibility, rugged construction and low applied voltages. These are contributing to growth in markets such as traffic lights, automotive brake signals and instrument displays, video displays, traffic signals, decorative signs and the many uses of the new white LED-based products. A new developments are directed to various materials used for high brightness HB-LED,s based on AlGaAs (red), AlInGaP (yellow-green to red) and InGaN (blue, green and white) devices. The development of LED,s depends on epitaxial growth advances, mainly molecular beam epitaxy (MBE) and metalorganic vapor phase epitaxy (MOVPE). As a technology improved, the performace of visible LED,s increased at the rate 10x per decade from less than 0.1 lm/W to the best red and orange LED,s now providing about 100 lm/W. The main engineering challenge is now the extraction or the ability to get all the light out of the chip to where it is needed. This has led to novel changes in the shape of the LED chip and to the replacement of GaAs with transparent GaP substrate throught wafer bonding after the LED has been produced. Most of the focus for nitride devices (InGaN) is to develop improved or new substrate materials to replace sapphire and enable the growth of lower defect density materials. Organic LED,s (OLED,s) have been undergone dramatic improvements in performace in the last five years. Two main technologies for OLED,s have emerged in the last decade, either based on conjaguated polymers, or sublimed films of small molecules. Recent improvements have taken OLED,s to luminous efficiency greater than 20 lm/W. However, in contrast to conventional LED,s, OLED,s share many of the properties associated with other organic substances and polymers. They allow more design flexibility than inorganic LED,s and thus lead to the high

  13. Engineering Strain for Improved III-Nitride Optoelectronic Device Performance

    Science.gov (United States)

    Van Den Broeck, Dennis Marnix

    Due to growing environmental and economic concerns, renewable energy generation and high-efficiency lighting are becoming even more important in the scientific community. III-Nitride devices have been essential in production of high-brightness light-emitting diodes (LEDs) and are now entering the photovoltaic (PV) realm as the technology advances. InGaN/GaN multiple quantum well LEDs emitting in the blue/green region have emerged as promising candidates for next-generation lighting technologies. Due to the large lattice mismatch between InN and GaN, large electric fields exist within the quantum well layers and result in low rates of radiative recombination, especially for the green spectral region. This is commonly referred to as the "green gap" and results in poor external quantum efficiencies for light-emitting diodes and laser diodes. In order to mitigate the compressive stress of InGaN QWs, a novel growth technique is developed in order to grown thick, strain-relaxed In yGa1-yN templates for 0.08 structure, "semibulk" InGaN templates were achieved with vastly superior crystal and optical properties than bulk InGaN films. These semibulk InGaN templates were then utilized as new templates for multiple quantum well active layers, effectively reducing the compressive strain in the InGaN wells due to the larger lattice constant of the InGaN template with respect to a GaN template. A zero-stress balance method was used in order to realize a strain-balanced multiple quantum well structure, which again showed improved optical characteristics when compared to fully-strain active regions. The semibulk InGaN template was then implemented into "strain-compensated" LED structures, where light emission was achieved with very little leakage current. Discussion of these strain-compensated devices compared to conventional LEDs is detailed.

  14. An optoelectronic integrated device including a laser and its driving circuit

    Energy Technology Data Exchange (ETDEWEB)

    Matsueda, H.; Nakano, H.; Tanaka, T.P.

    1984-10-01

    A monolithic optoelectronic integrated circuit (OEIC) including a laser diode, photomonitor and driving and detecting circuits has been fabricated on a semi-insulating GaAs substrate. The OEIC has a horizontal integrating structure which is suitable for realising high-density multifunctional devices. The fabricating process and the static and dynamic characteristics of the optical and electronic elements are described. The preliminary results of the co-operative operation of the laser and its driving circuit are also presented.

  15. Electronic Processes at Organic−Organic Interfaces: Insight from Modeling and Implications for Opto-electronic Devices

    KAUST Repository

    Beljonne, David; Cornil, Jérôme; Muccioli, Luca; Zannoni, Claudio; Brédas, Jean-Luc; Castet, Frédéric

    2011-01-01

    We report on the recent progress achieved in modeling the electronic processes that take place at interfaces between π-conjugated materials in organic opto-electronic devices. First, we provide a critical overview of the current computational

  16. Secondary treatment of films of colloidal quantum dots for optoelectronics and devices produced thereby

    Science.gov (United States)

    Semonin, Octavi Escala; Luther, Joseph M; Beard, Matthew C; Chen, Hsiang-Yu

    2014-04-01

    A method of forming an optoelectronic device. The method includes providing a deposition surface and contacting the deposition surface with a ligand exchange chemical and contacting the deposition surface with a quantum dot (QD) colloid. This initial process is repeated over one or more cycles to form an initial QD film on the deposition surface. The method further includes subsequently contacting the QD film with a secondary treatment chemical and optionally contacting the surface with additional QDs to form an enhanced QD layer exhibiting multiple exciton generation (MEG) upon absorption of high energy photons by the QD active layer. Devices having an enhanced QD active layer as described above are also disclosed.

  17. Optoelectronic devices, low temperature preparation methods, and improved electron transport layers

    KAUST Repository

    Eita, Mohamed S.

    2016-08-04

    An optoelectronic device such as a photovoltaic device which has at least one layer, such as an electron transport layer, which comprises a plurality of alternating, oppositely charged layers including metal oxide layers. The metal oxide can be zinc oxide. The plurality of layers can be prepared by layer-by-layer processing in which alternating layers are built up step-by-step due to electrostatic attraction. The efficiency of the device can be increased by this processing method compared to a comparable method like sputtering. The number of layers can be controlled to improve device efficiency. Aqueous solutions can be used which is environmentally friendly. Annealing can be avoided. A quantum dot layer can be used next to the metal oxide layer to form a quantum dot heterojunction solar device.

  18. CMOS On-Chip Optoelectronic Neural Interface Device with Integrated Light Source for Optogenetics

    International Nuclear Information System (INIS)

    Sawadsaringkarn, Y; Kimura, H; Maezawa, Y; Nakajima, A; Kobayashi, T; Sasagawa, K; Noda, T; Tokuda, T; Ohta, J

    2012-01-01

    A novel optoelectronic neural interface device is proposed for target applications in optogenetics for neural science. The device consists of a light emitting diode (LED) array implemented on a CMOS image sensor for on-chip local light stimulation. In this study, we designed a suitable CMOS image sensor equipped with on-chip electrodes to drive the LEDs, and developed a device structure and packaging process for LED integration. The prototype device produced an illumination intensity of approximately 1 mW with a driving current of 2.0 mA, which is expected to be sufficient to activate channelrhodopsin (ChR2). We also demonstrated the functions of light stimulation and on-chip imaging using a brain slice from a mouse as a target sample.

  19. Physical concepts of materials for novel optoelectronic device applications II: Device physics and applications; Proceedings of the Meeting, Aachen, Federal Republic of Germany, Oct. 28-Nov. 2, 1990

    International Nuclear Information System (INIS)

    Razeghi, M.

    1991-01-01

    The present conference on physical concepts for materials for novel optoelectronic device applications encompasses the device physics and applications including visible, IR, and far-IR sources, optoelectronic quantum devices, the physics and applications of high-Tc superconducting materials, photodetectors and modulators, and the electronic properties of heterostructures. Other issues addressed include semiconductor waveguides for optical switching, wide band-gap semiconductors, Si and Si-Ge alloys, transport phenomena in heterostructures and quantum wells, optoelectronic integrated circuits, nonlinear optical phenomena in bulk and multiple quantum wells, and optoelectronic technologies for microwave applications. Also examined are optical computing, current transport in charge-injection devices, thin films of YBaCuO for electronic applications, indirect stimulated emission at room temperature in the visible range, and a laser with active-element rectangular geometry

  20. Simultaneous topographical, electrical and optical microscopy of optoelectronic devices at the nanoscale

    KAUST Repository

    Kumar, Naresh

    2017-01-12

    Novel optoelectronic devices rely on complex nanomaterial systems where the nanoscale morphology and local chemical composition are critical to performance. However, the lack of analytical techniques that can directly probe these structure-property relationships at the nanoscale presents a major obstacle to device development. In this work, we present a novel method for non-destructive, simultaneous mapping of the morphology, chemical composition and photoelectrical properties with <20 nm spatial resolution by combining plasmonic optical signal enhancement with electrical-mode scanning probe microscopy. We demonstrate that this combined approach offers subsurface sensitivity that can be exploited to provide molecular information with a nanoscale resolution in all three spatial dimensions. By applying the technique to an organic solar cell device, we show that the inferred surface and subsurface composition distribution correlates strongly with the local photocurrent generation and explains macroscopic device performance. For instance, the direct measurement of fullerene phase purity can distinguish between high purity aggregates that lead to poor performance and lower purity aggregates (fullerene intercalated with polymer) that result in strong photocurrent generation and collection. We show that the reliable determination of the structure-property relationship at the nanoscale can remove ambiguity from macroscopic device data and support the identification of the best routes for device optimisation. The multi-parameter measurement approach demonstrated herein is expected to play a significant role in guiding the rational design of nanomaterial-based optoelectronic devices, by opening a new realm of possibilities for advanced investigation via the combination of nanoscale optical spectroscopy with a whole range of scanning probe microscopy modes.

  1. Nanopatterned Metallic Films for Use As Transparent Conductive Electrodes in Optoelectronic Devices

    KAUST Repository

    Catrysse, Peter B.

    2010-08-11

    We investigate the use of nanopatterned metallic films as transparent conductive electrodes in optoelectronic devices. We find that the physics of nanopatterned electrodes, which are often optically thin metallic films, differs from that of optically thick metallic films. We analyze the optical properties when performing a geometrical transformation that maintains the electrical properties. For one-dimensional patterns of metallic wires, the analysis favors tall and narrow wires. Our design principles remain valid for oblique incidence and readily carry over to two-dimensional patterns. © 2010 American Chemical Society.

  2. Extreme Radiation Hardness and Space Qualification of AlGaN Optoelectronic Devices

    International Nuclear Information System (INIS)

    Sun, Ke-Xun; MacNeil, Lawrence; Balakrishnan, Kathik; Hultgren, Eric; Goebel, John; Bilenko, Yuri; Yang, Jinwei; Sun, Wenhong; Shatalov, Max; Hu, Xuhong; Gaska, Remis

    2010-01-01

    Unprecedented radiation hardness and environment robustness are required in the new generation of high energy density physics (HEDP) experiments and deep space exploration. National Ignition Facility (NIF) break-even shots will have a neutron yield of 10 15 or higher. The Europa Jupiter System Mission (EJSM) mission instruments will be irradiated with a total fluence of 10 12 protons/cm 2 during the space journey. In addition, large temperature variations and mechanical shocks are expected in these applications under extreme conditions. Hefty radiation and thermal shields are required for Si and GaAs based electronics and optoelectronics devices. However, for direct illumination and imaging applications, shielding is not a viable option. It is an urgent task to search for new semiconductor technologies and to develop radiation hard and environmentally robust optoelectronic devices. We will report on our latest systematic experimental studies on radiation hardness and space qualifications of AlGaN optoelectronic devices: Deep UV Light Emitting Diodes (DUV LEDs) and solarblind UV Photodiodes (PDs). For custom designed AlGaN DUV LEDs with a central emission wavelength of 255 nm, we have demonstrated its extreme radiation hardness up to 2 x 10 12 protons/cm 2 with 63.9 MeV proton beams. We have demonstrated an operation lifetime of over 26,000 hours in a nitrogen rich environment, and 23,000 hours of operation in vacuum without significant power drop and spectral shift. The DUV LEDs with multiple packaging styles have passed stringent space qualifications with 14 g random vibrations, and 21 cycles of 100K temperature cycles. The driving voltage, current, emission spectra and optical power (V-I-P) operation characteristics exhibited no significant changes after the space environmental tests. The DUV LEDs will be used for photoelectric charge management in space flights. For custom designed AlGaN UV photodiodes with a central response wavelength of 255 nm, we have

  3. Direct Photolithography on Molecular Crystals for High Performance Organic Optoelectronic Devices.

    Science.gov (United States)

    Yao, Yifan; Zhang, Lei; Leydecker, Tim; Samorì, Paolo

    2018-05-23

    Organic crystals are generated via the bottom-up self-assembly of molecular building blocks which are held together through weak noncovalent interactions. Although they revealed extraordinary charge transport characteristics, their labile nature represents a major drawback toward their integration in optoelectronic devices when the use of sophisticated patterning techniques is required. Here we have devised a radically new method to enable the use of photolithography directly on molecular crystals, with a spatial resolution below 300 nm, thereby allowing the precise wiring up of multiple crystals on demand. Two archetypal organic crystals, i.e., p-type 2,7-diphenyl[1]benzothieno[3,2- b][1]benzothiophene (Dph-BTBT) nanoflakes and n-type N, N'-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) nanowires, have been exploited as active materials to realize high-performance top-contact organic field-effect transistors (OFETs), inverter and p-n heterojunction photovoltaic devices supported on plastic substrate. The compatibility of our direct photolithography technique with organic molecular crystals is key for exploiting the full potential of organic electronics for sophisticated large-area devices and logic circuitries, thus paving the way toward novel applications in plastic (opto)electronics.

  4. RIR-MAPLE deposition of conjugated polymers and hybrid nanocomposites for application to optoelectronic devices

    International Nuclear Information System (INIS)

    Stiff-Roberts, Adrienne D.; Pate, Ryan; McCormick, Ryan; Lantz, Kevin R.

    2012-01-01

    Resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) is a variation of pulsed laser deposition that is useful for organic-based thin films because it reduces material degradation by selective absorption of infrared radiation in the host matrix. A unique emulsion-based RIR-MAPLE approach has been developed that reduces substrate exposure to solvents and provides controlled and repeatable organic thin film deposition. In order to establish emulsion-based RIR-MAPLE as a preferred deposition technique for conjugated polymer or hybrid nanocomposite optoelectronic devices, studies have been conducted to demonstrate the value added by the approach in comparison to traditional solution-based deposition techniques, and this work will be reviewed. The control of hybrid nanocomposite thin film deposition, and the photoconductivity in such materials deposited using emulsion-based RIR-MAPLE, will also be reviewed. The overall result of these studies is the demonstration of emulsion-based RIR-MAPLE as a viable option for the fabrication of conjugated polymer and hybrid nanocomposite optoelectronic devices that could yield improved device performance.

  5. Advanced Optoelectronic Devices based on Si Quantum Dots/Si Nanowires Hetero-structures

    International Nuclear Information System (INIS)

    Xu, J; Zhai, Y Y; Cao, Y Q; Chen, K J

    2017-01-01

    Si quantum dots are currently extensively studied since they can be used to develop many kinds of optoelectronic devices. In this report, we review the fabrication of Si quantum dots (Si QD) /Si nanowires (Si NWs) hetero-structures by deposition of Si QDs/SiO 2 or Si QDs/SiC multilayers on Si NWs arrays. The electroluminescence and photovoltaic devices based on the formed hetero-structures have been prepared and the improved performance is confirmed. It is also found that the surface recombination via the surface defects states on the Si NWs, especially the ones obtained by the long-time etching, may deteriorate the device properties though they exhibit the better anti-reflection characteristics. The possible surface passivation approaches are briefly discussed. (paper)

  6. Recent developments of truly stretchable thin film electronic and optoelectronic devices.

    Science.gov (United States)

    Zhao, Juan; Chi, Zhihe; Yang, Zhan; Chen, Xiaojie; Arnold, Michael S; Zhang, Yi; Xu, Jiarui; Chi, Zhenguo; Aldred, Matthew P

    2018-03-29

    Truly stretchable electronics, wherein all components themselves permit elastic deformation as the whole devices are stretched, exhibit unique advantages over other strategies, such as simple fabrication process, high integrity of entire components and intimate integration with curvilinear surfaces. In contrast to the stretchable devices using stretchable interconnectors to integrate with rigid active devices, truly stretchable devices are realized with or without intentionally employing structural engineering (e.g. buckling), and the whole device can be bent, twisted, or stretched to meet the demands for practical applications, which are beyond the capability of conventional flexible devices that can only bend or twist. Recently, great achievements have been made toward truly stretchable electronics. Here, the contribution of this review is an effort to provide a panoramic view of the latest progress concerning truly stretchable electronic devices, of which we give special emphasis to three kinds of thin film electronic and optoelectronic devices: (1) thin film transistors, (2) electroluminescent devices (including organic light-emitting diodes, light-emitting electrochemical cells and perovskite light-emitting diodes), and (3) photovoltaics (including organic photovoltaics and perovskite solar cells). We systematically discuss the device design and fabrication strategies, the origin of device stretchability and the relationship between the electrical and mechanical behaviors of the devices. We hope that this review provides a clear outlook of these attractive stretchable devices for a broad range of scientists and attracts more researchers to devote their time to this interesting research field in both industry and academia, thus encouraging more intelligent lifestyles for human beings in the coming future.

  7. Organic optoelectronics

    CERN Document Server

    Hu, Wenping; Gong, Xiong; Zhan, Xiaowei; Fu, Hongbing; Bjornholm, Thomas

    2012-01-01

    Written by internationally recognized experts in the field with academic as well as industrial experience, this book concisely yet systematically covers all aspects of the topic.The monograph focuses on the optoelectronic behavior of organic solids and their application in new optoelectronic devices. It covers organic electroluminescent materials and devices, organic photonics, materials and devices, as well as organic solids in photo absorption and energy conversion. Much emphasis is laid on the preparation of functional materials and the fabrication of devices, from materials synthesis a

  8. Optimization of light out-coupling in optoelectronic devices using nanostructured surface

    DEFF Research Database (Denmark)

    Ou, Haiyan; Ou, Yiyu; Argyraki, Aikaterini

    C and GaN, these developed methods could be applied to other semicon ductors such as Si, etc. Furthermore, all optoelectronic devices having an optical interface such as solar cells, photo - detectors, could benefit from these developed methods for opto - electronic performance improvement....... the overall efficiency of the LEDs. In this paper we have developed various methods for two important semiconductors: silicon carbide (SiC) and gallium nitride (GaN), and demonstrated enormous extraction efficiency enhancement. SiC is an important su bstrate for LED devices. It has refractive index of 2.......6, and only a few percent of light could escape from it. We have developed periodic nanocone structures by using electron - beam lithography, periodic nanodome structures by using nanosphere lithography, random nanostructures by using self - assembled metal nanoparticles, and random nanostructures by directly...

  9. Nanocellulose-based Translucent Diffuser for Optoelectronic Device Applications with Dramatic Improvement of Light Coupling.

    Science.gov (United States)

    Wu, Wei; Tassi, Nancy G; Zhu, Hongli; Fang, Zhiqiang; Hu, Liangbing

    2015-12-09

    Nanocellulose is a biogenerated and biorenewable organic material. Using a process based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)/NaClO/NaBr system, a highly translucent and light-diffusive film consisting of many layers of nanocellulose fibers and wood pulp microfibers was made. The film demonstrates a combination of large optical transmittance of ∼90% and tunable diffuse transmission of up to ∼78% across the visible and near-infrared spectra. The detailed characterizations of the film indicate the combination of high optical transmittance and haze is due to the film's large packing density and microstructured surface. The superior optical properties make the film a translucent light diffuser and applicable for improving the efficiencies of optoelectronic devices such as thin-film silicon solar cells and organic light-emitting devices.

  10. Role of vacancy defects in Al doped ZnO thin films for optoelectronic devices

    Science.gov (United States)

    Rotella, H.; Mazel, Y.; Brochen, S.; Valla, A.; Pautrat, A.; Licitra, C.; Rochat, N.; Sabbione, C.; Rodriguez, G.; Nolot, E.

    2017-12-01

    We report on the electrical, optical and photoluminescence properties of industry-ready Al doped ZnO thin films grown by physical vapor deposition, and their evolution after annealing under vacuum. Doping ZnO with Al atoms increases the carrier density but also favors the formation of Zn vacancies, thereby inducing a saturation of the conductivity mechanism at high aluminum content. The electrical and optical properties of these thin layered materials are both improved by annealing process which creates oxygen vacancies that releases charge carriers thus improving the conductivity. This study underlines the effect of the formation of extrinsic and intrinsic defects in Al doped ZnO compound during the fabrication process. The quality and the optoelectronic response of the produced films are increased (up to 1.52 mΩ \\cdotcm and 3.73 eV) and consistent with the industrial device requirements.

  11. Optoelectronic device physics and technology of nitride semiconductors from the UV to the terahertz

    Science.gov (United States)

    Moustakas, Theodore D.; Paiella, Roberto

    2017-10-01

    This paper reviews the device physics and technology of optoelectronic devices based on semiconductors of the GaN family, operating in the spectral regions from deep UV to Terahertz. Such devices include LEDs, lasers, detectors, electroabsorption modulators and devices based on intersubband transitions in AlGaN quantum wells (QWs). After a brief history of the development of the field, we describe how the unique crystal structure, chemical bonding, and resulting spontaneous and piezoelectric polarizations in heterostructures affect the design, fabrication and performance of devices based on these materials. The heteroepitaxial growth and the formation and role of extended defects are addressed. The role of the chemical bonding in the formation of metallic contacts to this class of materials is also addressed. A detailed discussion is then presented on potential origins of the high performance of blue LEDs and poorer performance of green LEDs (green gap), as well as of the efficiency reduction of both blue and green LEDs at high injection current (efficiency droop). The relatively poor performance of deep-UV LEDs based on AlGaN alloys and methods to address the materials issues responsible are similarly addressed. Other devices whose state-of-the-art performance and materials-related issues are reviewed include violet-blue lasers, ‘visible blind’ and ‘solar blind’ detectors based on photoconductive and photovoltaic designs, and electroabsorption modulators based on bulk GaN or GaN/AlGaN QWs. Finally, we describe the basic physics of intersubband transitions in AlGaN QWs, and their applications to near-infrared and terahertz devices.

  12. A Novel Optoelectronic Device Based on Correlated Two-Dimensional Fermions

    Science.gov (United States)

    Dianat, Pouya

    Conventional metallic contacts can be replicated by quantum two dimensional charge (of Fermion) systems (2DFS). Unlike metals, the particle concentration of these "unconventional" systems can be accurately controlled in an extensive range and by means of external electronic or optical stimuli. A 2DFS can, hence, transition from a high-density kinetic liquid into a dilute-but highly correlated-gas state, in which inter-particle Coulombic interactions are significant. Such interactions contribute negatively, by so-called exchange-correlation energies, to the overall energetics of the system, and are manifested as a series negative quantum capacitance. This dissertation investigates the capacitive performance of a class of unconventional devices based on a planar metal-semiconductor-metal structure with an embedded 2DFS. They constitute an opto-electronically controlled variable capacitor, with record breaking figures-of-merit in capacitance tuning ranges of up to 7000 and voltage sensitivities as large as 400. Internal eld manipulations by localized depletion of a dense 2DFS account for the enlarged maximum and reduced minimum capacitances. The capacitance-voltage characteristics of these devices incur an anomalous "Batman" shape capacitance enhancement (CE) of up to 200% that may be triggered optically. The CE is attributed to the release and storage of exchange-correlation energies; from the "unconventional" plate and in the dielectric, respectively. This process is enforced by density manipulation of the 2DFS by a hybrid of an external eld and light-generated carriers. Under moderate optical powers, the capacitance becomes 43 times greater than the dark value; thus a new capacitance-based photodetection method is offered. This new capacitance based photodetection method has a range of applications in optoelectronics, particularly in the next generation of photonic integrated systems.

  13. Stress-corrosion cracking of indium tin oxide coated polyethylene terephthalate for flexible optoelectronic devices

    International Nuclear Information System (INIS)

    Sierros, Konstantinos A.; Morris, Nicholas J.; Ramji, Karpagavalli; Cairns, Darran R.

    2009-01-01

    Stress corrosion cracking of transparent conductive layers of indium tin oxide (ITO), sputtered on polyethylene terephthalate (PET) substrates, is an issue of paramount importance in flexible optoelectronic devices. These components, when used in flexible device stacks, can be in contact with acid containing pressure-sensitive adhesives or with conductive polymers doped in acids. Acids can corrode the brittle ITO layer, stress can cause cracking and delamination, and stress-corrosion cracking can cause more rapid failure than corrosion alone. The combined effect of an externally-applied mechanical stress to bend the device and the corrosive environment provided by the acid is investigated in this work. We show that acrylic acid which is contained in many pressure-sensitive adhesives can cause corrosion of ITO coatings on PET. We also investigate and report on the combined effect of external mechanical stress and corrosion on ITO-coated PET composite films. Also, it is shown that the combination of stress and corrosion by acrylic acid can cause ITO cracking to occur at stresses less than a quarter of those needed for failure with no corrosion. In addition, the time to failure, under ∼ 1% tensile strain can reduce the total time to failure by as much as a third

  14. Mechano-chemical degradation of flexible electrodes for optoelectronic device applications

    International Nuclear Information System (INIS)

    Bejitual, T.S.; Morris, N.J.; Cronin, S.D.; Cairns, D.R.; Sierros, K.A.

    2013-01-01

    The electrical, optical, and structural integrity of flexible transparent electrodes is of paramount importance in the design and fabrication of optoelectronic devices such as organic light emitting diodes, liquid crystal displays, touch panels, solar cells, and solid-state lighting. The electrodes may corrode due to acid-containing pressure sensitive adhesives present in the device stacks. In addition, structural failure may occur due to external applied loading. The combined action and further accumulation of both repeated mechanical loading and corrosion can aggravate the loss of functionality of the electrodes. In this study we investigate, using the design of experimental methods, the effects of corrosion, applied mechanical strain, film thickness, and number of bending cycles on the electrical and structural integrity of indium tin oxide (ITO) and carbon nanotube (CNT) films both coated on polyethylene terephthalate (PET) substrates. In situ electrical resistance measurements suggest that fatigue-corrosion is found to be the most critical failure mode for the ITO-based coatings. For example, the change in ITO electrical resistance increase under fatigue-corrosion (1% strain, 150,000 cycles) is 5.8 times higher than that of fatigue mode alone. On the other hand, a minimum change in electrical resistance of the CNT-based electrodes is found when applying the same conditions. - Highlights: • Combined mechano-chemical effects on electrode durability. • CNT-based electrodes outperform ITO counterparts. • Importance of combined fatigue and corrosion action on device reliability

  15. Tungsten oxides as interfacial layers for improved performance in hybrid optoelectronic devices

    International Nuclear Information System (INIS)

    Vasilopoulou, M.; Palilis, L.C.; Georgiadou, D.G.; Argitis, P.; Kennou, S.; Kostis, I.; Papadimitropoulos, G.; Stathopoulos, N.A.; Iliadis, A.A.; Konofaos, N.; Davazoglou, D.; Sygellou, L.

    2011-01-01

    Tungsten oxide (WO 3 ) films with thicknesses ranging from 30 to 100 nm were grown by Hot Filament Vapor Deposition (HFVD). Films were studied by X-Ray Photoemission Spectroscopy (XPS) and were found to be stoichiometric. The surface morphology of the films was characterized by Atomic Force Microscopy (AFM). Samples had a granular form with grains in the order of 100 nm. The surface roughness was found to increase with film thickness. HFVD WO 3 films were used as conducting interfacial layers in advanced hybrid organic-inorganic optoelectronic devices. Hybrid-Organic Light Emitting Diodes (Hy-OLEDs) and Organic Photovoltaics (Hy-OPVs) were fabricated with these films as anode and/or as cathode interfacial conducting layers. The Hy-OLEDs showed significantly higher current density and a lower turn-on voltage when a thin WO 3 layer was inserted at the anode/polymer interface, while when inserted at the cathode/polymer interface the device performance was found to deteriorate. The improvement was attributed to a more efficient hole injection and transport from the Fermi level of the anode to the Highest Occupied Molecular Orbital (HOMO) of a yellow emitting copolymer (YEP). On the other hand, the insertion of a thin WO 3 layer at the cathode/polymer interface of Hy-OPV devices based on a polythiophene-fullerene bulk-heterojunction blend photoactive layer resulted in an increase of the produced photogenerated current, more likely due to improved electron extraction at the Al cathode.

  16. Mechano-chemical degradation of flexible electrodes for optoelectronic device applications

    Energy Technology Data Exchange (ETDEWEB)

    Bejitual, T.S.; Morris, N.J.; Cronin, S.D.; Cairns, D.R.; Sierros, K.A., E-mail: kostas.sierros@mail.wvu.edu

    2013-12-31

    The electrical, optical, and structural integrity of flexible transparent electrodes is of paramount importance in the design and fabrication of optoelectronic devices such as organic light emitting diodes, liquid crystal displays, touch panels, solar cells, and solid-state lighting. The electrodes may corrode due to acid-containing pressure sensitive adhesives present in the device stacks. In addition, structural failure may occur due to external applied loading. The combined action and further accumulation of both repeated mechanical loading and corrosion can aggravate the loss of functionality of the electrodes. In this study we investigate, using the design of experimental methods, the effects of corrosion, applied mechanical strain, film thickness, and number of bending cycles on the electrical and structural integrity of indium tin oxide (ITO) and carbon nanotube (CNT) films both coated on polyethylene terephthalate (PET) substrates. In situ electrical resistance measurements suggest that fatigue-corrosion is found to be the most critical failure mode for the ITO-based coatings. For example, the change in ITO electrical resistance increase under fatigue-corrosion (1% strain, 150,000 cycles) is 5.8 times higher than that of fatigue mode alone. On the other hand, a minimum change in electrical resistance of the CNT-based electrodes is found when applying the same conditions. - Highlights: • Combined mechano-chemical effects on electrode durability. • CNT-based electrodes outperform ITO counterparts. • Importance of combined fatigue and corrosion action on device reliability.

  17. FY1995 optoelectronic devices and circuits for terabit class network; 1995 nendo terabit kyu network yo hikari denshi device kairo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The necessary technology realizing Terabit class optical network is the signal multiplexing both in temporal and spectral domains. Controllability of ultrafast optoelectronic systems is therefore the priority issue. Specifically we chose semiconductor lasers as the key devices. The methodology for performance improvement and the creation of novel functionality are investigated. Firstly compression of semiconductor laser pulse reached the world record of 65 femto second. Secondly a proposal was made to control mode locked semiconductor lasers via subharmonic synchronization and a substantial phase noise reduction was demonstrated. Thirdly a new technology was developed to realize broadband anti-reflection coating on semiconductor laser amplifier facet, bringing about significant performance improvement. To compensate the dispersion induced signal distortion a broadband semiconductor laser amplifier four wave mixing was analyzed and also demonstrated experimentally. (NEDO)

  18. Development of aluminum gallium nitride based optoelectronic devices operating in deep UV and terahertz spectrum ranges

    Science.gov (United States)

    Zhang, Wei

    In this research project I have investigated AlGaN alloys and their quantum structures for applications in deep UV and terahertz optoelectronic devices. For the deep UV emitter applications the materials and devices were grown by rf plasma-assisted molecular beam epitaxy on 4H-SiC, 6H-SiC and c-plane sapphire substrates. In the growth of AlGaN/AlN multiple quantum wells on SiC substrates, the AlGaN wells were grown under excess Ga, far beyond than what is required for the growth of stoichiometric AlGaN films, which resulted in liquid phase epitaxy growth mode. Due to the statistical variations of the excess Ga on the growth front we found that this growth mode leads to films with lateral variations in the composition and thus, band structure potential fluctuations. Transmission electron microscopy shows that the wells in such structures are not homogeneous but have the appearance of quantum dots. We find by temperature dependent photoluminescence measurements that the multiple quantum wells with band structure potential fluctuations emit at 240 nm and have room temperature internal quantum efficiency as high as 68%. Furthermore, they were found to have a maximum net modal optical gain of 118 cm-1 at a transparency threshold corresponding to 1.4 x 1017 cm-3 excited carriers. We attribute this low transparency threshold to population inversion of only the regions of the potential fluctuations rather than of the entire matrix. Some prototype deep UV emitting LED structures were also grown by the same method on sapphire substrates. Optoelectronic devices for terahertz light emission and detection, based on intersubband transitions in III-nitride semiconductor quantum wells, were grown on single crystal c-plane GaN substrates. Growth conditions such the ratio of group III to active nitrogen fluxes, which determines the appropriate Ga-coverage for atomically smooth growth without requiring growth interruptions were employed. Emitters designed in the quantum cascade

  19. Investigational Clinical Trial of a Prototype Optoelectronic Computer-Aided Navigation Device for Dental Implant Surgery.

    Science.gov (United States)

    Jokstad, Asbjørn; Winnett, Brenton; Fava, Joseph; Powell, David; Somogyi-Ganss, Eszter

    New digital technologies enable real-time computer-aided (CA) three-dimensional (3D) guidance during dental implant surgery. The aim of this investigational clinical trial was to demonstrate the safety and effectiveness of a prototype optoelectronic CA-navigation device in comparison with the conventional approach for planning and effecting dental implant surgery. Study participants with up to four missing teeth were recruited from the pool of patients referred to the University of Toronto Graduate Prosthodontics clinic. The first 10 participants were allocated to either a conventional or a prototype device study arm in a randomized trial. The next 10 participants received implants using the prototype device. All study participants were restored with fixed dental prostheses after 3 (mandible) or 6 (maxilla) months healing, and monitored over 12 months. The primary outcome was the incidence of any surgical, biologic, or prosthetic adverse events or device-related complications. Secondary outcomes were the incidence of positioning of implants not considered suitable for straightforward prosthetic restoration (yes/no); the perception of the ease of use of the prototype device by the two oral surgeons, recorded by use of a Likert-type questionnaire; and the clinical performance of the implant and superstructure after 1 year in function. Positioning of the implants was appraised on periapical radiographs and clinical photographs by four independent blinded examiners. Peri-implant bone loss was measured on periapical radiographs by a blinded examiner. No adverse events occurred related to placing any implants. Four device-related complications led to a switch from using the prototype device to the conventional method. All implants placed by use of the prototype device were in a position considered suitable for straightforward prosthetic restoration (n = 21). The qualitative evaluation by the surgeons was generally positive, although ergonomic challenges were identified

  20. Characteristics of the Current-Controlled Phase Transition of VO2 Microwires for Hybrid Optoelectronic Devices

    Directory of Open Access Journals (Sweden)

    Arash Joushaghani

    2015-08-01

    Full Text Available The optical and electrical characteristics of the insulator-metal phase transition of vanadium dioxide (VO2 enable the realization of power-efficient, miniaturized hybrid optoelectronic devices. This work studies the current-controlled, two-step insulator-metal phase transition of VO2 in varying microwire geometries. Geometry-dependent scaling trends extracted from current-voltage measurements show that the first step induced by carrier injection is delocalized over the microwire, while the second, thermally-induced step is localized to a filament about 1 to 2 μm wide for 100 nm-thick sputtered VO2 films on SiO2. These effects are confirmed by direct infrared imaging, which also measures the change in optical absorption in the two steps. The difference between the threshold currents of the two steps increases as the microwires are narrowed. Micron- and sub-micron-wide VO2 structures can be used to separate the two phase transition steps in photonic and electronic devices.

  1. ACCURACY COMPARISON OF ALGORITHMS FOR DETERMINATION OF IMAGE CENTER COORDINATES IN OPTOELECTRONIC DEVICES

    Directory of Open Access Journals (Sweden)

    N. A. Starasotnikau

    2018-01-01

    Full Text Available Accuracy in determination of coordinates for image having simple shapes is considered as one of important and significant parameters in metrological optoelectronic systems such as autocollimators, stellar sensors, Shack-Hartmann sensors, schemes for geometric calibration of digital cameras for aerial and space imagery, various tracking systems. The paper describes a mathematical model for a measuring stand based on a collimator which projects a test-object onto a photodetector of an optoelectronic device. The mathematical model takes into account characteristic noises for photodetectors: a shot noise of the desired signal (photon and a shot noise of a dark signal, readout and spatial heterogeneity of CCD (charge-coupled device matrix elements. In order to reduce noise effect it is proposed to apply the Wiener filter for smoothing an image and its unambiguous identification and also enter a threshold according to brightness level. The paper contains a comparison of two algorithms for determination of coordinates in accordance with energy gravity center and contour. Sobel, Pruitt, Roberts, Laplacian Gaussian, Canni detectors have been used for determination of the test-object contour. The essence of the algorithm for determination of coordinates lies in search for an image contour in the form of a circle with its subsequent approximation and determination of the image center. An error calculation has been made while determining coordinates of a gravity center for test-objects of various diameters: 5, 10, 20, 30, 40, 50 pixels of a photodetector and also signalto-noise ratio values: 200, 100, 70, 20, 10. Signal-to-noise ratio has been calculated as a difference between maximum image intensity of the test-object and the background which is divided by mean-square deviation of the background. The accuracy for determination of coordinates has been improved by 0.5-1 order in case when there was an increase in a signal-to-noise ratio. Accuracy

  2. One-dimensional CuO nanowire: synthesis, electrical, and optoelectronic devices application

    Science.gov (United States)

    Luo, Lin-Bao; Wang, Xian-He; Xie, Chao; Li, Zhong-Jun; Lu, Rui; Yang, Xiao-Bao; Lu, Jian

    2014-11-01

    In this work, we presented a surface mechanical attrition treatment (SMAT)-assisted approach to the synthesis of one-dimensional copper oxide nanowires (CuO NWs) for nanodevices applications. The as-prepared CuO NWs have diameter and the length of 50 ~ 200 nm and 5 ~ 20 μm, respectively, with a preferential growth orientation along [1 [InlineEquation not available: see fulltext.] 0] direction. Interestingly, nanofield-effect transistor (nanoFET) based on individual CuO NW exhibited typical p-type electrical conduction, with a hole mobility of 0.129 cm2V-1 s-1 and hole concentration of 1.34 × 1018 cm-3, respectively. According to first-principle calculations, such a p-type electrical conduction behavior was related to the oxygen vacancies in CuO NWs. What is more, the CuO NW device was sensitive to visible light illumination with peak sensitivity at 600 nm. The responsitivity, conductive gain, and detectivity are estimated to be 2.0 × 102 A W-1, 3.95 × 102 and 6.38 × 1011 cm Hz1/2 W-1, respectively, which are better than the devices composed of other materials. Further study showed that nanophotodetectors assembled on flexible polyethylene terephthalate (PET) substrate can work under different bending conditions with good reproducibility. The totality of the above results suggests that the present CuO NWs are potential building blocks for assembling high-performance optoelectronic devices.

  3. Surface engineered two-dimensional and quasi-one-dimensional nanomaterials for electronic and optoelectronic devices

    Science.gov (United States)

    Du, Xiang

    As the sizes of individual components in electronic and optoelectronic devices approach nano scale, the performance of the devices is often determined by surface properties due to their large surface-to-volume ratio. Surface phenomena have become one of the cornerstones in nanoelectronic industry. For this reason, research on the surface functionalization has been tremendous amount of growth over the past decades, and promises to be an increasingly important field in the future. Surface functionalization, as an effective technique to modify the surface properties of a material through a physical or chemical approach, exhibits great potential to solve the problems and challenges, and modulate the performance of nanomaterials based functional devices. Surface functionalization drives the developments and applications of modern electronic and optoelectronic devices fabricated by nanomaterials. In this thesis, I demonstrate two surface functionalization approaches, namely, surface transfer doping and H2 annealing, to effectively solve the problems and significantly enhance the performance of 2D (single structure black phosphorus (BP) and heterostructure graphene/Si Schottky junction), and quasi-1D (molybdenum trioxide (MoO 3) nanobelt) nanomaterials based functional devices, respectively. In situ photoelectron spectroscopy (PES) measurements were also carried out to explore the interfacial charge transfer occurring at the interface between the nanostructures and doping layers, and the gap states in MoO 3 thin films, which provides the underlying mechanism to understand and support our device measurement results. In the first part of this thesis, I will discuss the first surface functionalization approach, namely, surface transfer doping, to effectively modulate the ambipolar characteristics of 2D few-layer BP flakes based FETs. The ambipolar characteristics of BP transistors were effectively modulated through in situ surface functionalization with cesium carbonate (Cs2

  4. Electronic and optoelectronic device applications based on ReS2

    Science.gov (United States)

    Liu, Erfu; Long, Mingsheng; Wang, Yaojia; Pan, Yiming; Ho, Chinghwa; Wang, Baigeng; Miao, Feng

    Rhenium disulfide (ReS2) is a unique semiconducting TMD with distorted 1T structure and weak interlayer coupling. We have previously investigated its in-plane anisotropic property and electronic applications on FET and digital inverters. In this talk, we will present high responsivity phototransistors based on few-layer ReS2. Depending on the back gate voltage, source drain bias and incident optical light intensity, the maximum attainable photoresponsivity can reach as high as 88,600 A W-1, which is one of the highest value among individual two-dimensional materials with similar device structures. Such high photoresponsivity is attributed to the increased light absorption as well as the gain enhancement due to the existence of trap states in the few-layer ReS2 flakes. The existence of trap states is proved by temperature dependent transport measurements. It further enables the detection of weak signals. Our studies underscore ReS2 as a promising material for future electronic and sensitive optoelectronic applications.

  5. Microscopic study on the carrier distribution in optoelectronic device structures: experiment and modeling

    Science.gov (United States)

    Huang, Wenchao; Xia, Hui; Wang, Shaowei; Deng, Honghai; Wei, Peng; Li, Lu; Liu, Fengqi; Li, Zhifeng; Li, Tianxin

    2011-12-01

    Scanning capacitance microscopy (SCM) and scanning spreading resistance microscopy (SSRM) both are capable of mapping the 2-demensional carrier distribution in semiconductor device structures, which is essential in determining their electrical and optoelectronic performances. In this work, cross-sectional SCM1,2 is used to study the InGaAs/InP P-i-N junctions prepared by area-selective p-type diffusion. The diffusion lengths in the depth as well as the lateral directions are obtained for junctions under different window sizes in mask, which imply that narrow windows may result in shallow p-n junctions. The analysis is beneficial to design and fabricate focal plane array of near infrared photodetectors with high duty-cycle and quantum efficiency. On the other hand, SSRM provides unparalleled spatial resolution (demanded for studying low-dimensional structures. However, to derive the carrier density from the measured local conductance in individual quantum structures, reliable model for SSRM is necessary but still not well established. Based on the carrier concentration related transport mechanisms, i.e. thermionic emission and thermionic field emission4,5, we developed a numerical model for the tip-sample Schottky contact4. The calculation is confronted with SSRM study on the dose-calibrated quantum wells (QWs).

  6. Heavy ion elastic recoil detection analysis of optoelectronic and semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Dytlewski, N; Cohen, D D [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Johnston, P; Walker, S [Royal Melbourne Inst. of Tech., VIC (Australia); Whitlow, H; Hult, M [Lund Univ. (Sweden); Oestling, M; Zaring, C [Royal Inst. of Tech., Stockholm (Sweden)

    1994-12-31

    In recent years, the use of heavy ion time-of-flight elastic recoil spectrometry (HIERDA) has been applied to analyse multi-phase, thin layer devices used in optoelectronics, semiconductors and solar power generation. HIERDA gives simultaneously, mass resolved elemental concentration vs depth profiles of the matrix constituents, and is particularly suited to the determination of light elements in a heavy matrix. The beam/target interaction process is similar to RBS, but has the difference that the recoiling target atoms are detected instead of the scattered projectile. High energy, heavy ions beams bombard the sample, ejecting recoil atoms which are detected at a forward angle of 45 deg. A time-of-flight and total energy detection system enables the ejected particle`s mass to be identified, and allows energy spectra to be obtained and interpreted in an analogous way to RBS, but with the important difference that the elemental spectra are separated, and not superimposed on a background as in RBS. Some of the measurements made with a HIERDA system on the ANTARES Tandem Accelerator at ANSTO are described. 1 refs., 4 figs.

  7. Hydrogen-Bonded Organic Semiconductor Micro- And Nanocrystals: From Colloidal Syntheses to (Opto-)Electronic Devices

    Science.gov (United States)

    2014-01-01

    Organic pigments such as indigos, quinacridones, and phthalocyanines are widely produced industrially as colorants for everyday products as various as cosmetics and printing inks. Herein we introduce a general procedure to transform commercially available insoluble microcrystalline pigment powders into colloidal solutions of variously sized and shaped semiconductor micro- and nanocrystals. The synthesis is based on the transformation of the pigments into soluble dyes by introducing transient protecting groups on the secondary amine moieties, followed by controlled deprotection in solution. Three deprotection methods are demonstrated: thermal cleavage, acid-catalyzed deprotection, and amine-induced deprotection. During these processes, ligands are introduced to afford colloidal stability and to provide dedicated surface functionality and for size and shape control. The resulting micro- and nanocrystals exhibit a wide range of optical absorption and photoluminescence over spectral regions from the visible to the near-infrared. Due to excellent colloidal solubility offered by the ligands, the achieved organic nanocrystals are suitable for solution processing of (opto)electronic devices. As examples, phthalocyanine nanowire transistors as well as quinacridone nanocrystal photodetectors, with photoresponsivity values by far outperforming those of vacuum deposited reference samples, are demonstrated. The high responsivity is enabled by photoinduced charge transfer between the nanocrystals and the directly attached electron-accepting vitamin B2 ligands. The semiconducting nanocrystals described here offer a cheap, nontoxic, and environmentally friendly alternative to inorganic nanocrystals as well as a new paradigm for obtaining organic semiconductor materials from commercial colorants. PMID:25253644

  8. Heavy ion elastic recoil detection analysis of optoelectronic and semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Dytlewski, N.; Cohen, D.D. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Johnston, P.; Walker, S. [Royal Melbourne Inst. of Tech., VIC (Australia); Whitlow, H.; Hult, M. [Lund Univ. (Sweden); Oestling, M.; Zaring, C. [Royal Inst. of Tech., Stockholm (Sweden)

    1993-12-31

    In recent years, the use of heavy ion time-of-flight elastic recoil spectrometry (HIERDA) has been applied to analyse multi-phase, thin layer devices used in optoelectronics, semiconductors and solar power generation. HIERDA gives simultaneously, mass resolved elemental concentration vs depth profiles of the matrix constituents, and is particularly suited to the determination of light elements in a heavy matrix. The beam/target interaction process is similar to RBS, but has the difference that the recoiling target atoms are detected instead of the scattered projectile. High energy, heavy ions beams bombard the sample, ejecting recoil atoms which are detected at a forward angle of 45 deg. A time-of-flight and total energy detection system enables the ejected particle`s mass to be identified, and allows energy spectra to be obtained and interpreted in an analogous way to RBS, but with the important difference that the elemental spectra are separated, and not superimposed on a background as in RBS. Some of the measurements made with a HIERDA system on the ANTARES Tandem Accelerator at ANSTO are described. 1 refs., 4 figs.

  9. Fused thiophene-based conjugated polymers and their use in optoelectronic devices

    Science.gov (United States)

    Facchetti, Antonio; Marks, Tobin J.; Takai, Atsuro; Seger, Mark; Chen; , Zhihua

    2017-07-18

    The present teachings relate to polymeric compounds and their use as organic semiconductors in organic and hybrid optical, optoelectronic, and/or electronic devices such as photovoltaic cells, light emitting diodes, light emitting transistors, and field effect transistors. The disclosed compounds generally include as repeating units at least one annulated thienyl-vinylene-thienyl (TVT) unit and at least one other pi-conjugated unit. The annulated TVT unit can be represented by the formula: ##STR00001## where Cy.sup.1 and Cy.sup.2 can be a five- or six-membered carbocyclic ring. The annulated TVT unit can be optionally substituted at any available ring atom(s), and can be covalently linked to the other pi-conjugated unit via either the thiophene rings or the carbocyclic rings Cy.sup.1 and Cy.sup.2. The other pi-conjugated unit can be a conjugated linear linker including one or more unsaturated bonds, or a conjugated cyclic linker including one or more carbocyclic and/or heterocyclic rings.

  10. Manipulation of Self-Assembled Microparticle Chains by Electroosmotic Flow Assisted Electrorotation in an Optoelectronic Device

    Directory of Open Access Journals (Sweden)

    Xiaolu Zhu

    2015-09-01

    Full Text Available A method incorporating the optically induced electrorotation (OER and alternating current electroosmotic (ACEO effects, for the formation and motion control of microparticle chains, is numerically and experimentally demonstrated. In this method, both the rotating electric field and ACEO fluid roll are generated around the border between light and dark area of the fluidic chamber in an optoelectronic tweezers (OET device. The experimental results show that the particle chains can self-rotate in their pitch axes under the rotating electric field produced due to the different impedances of the photoconductive layer in light and dark areas, and have a peak self-rotating rate at around 1 MHz. The orbital movement of entire particle chain around the center of ACEO fluid roll can be achieved from 0.5 to 600 kHz. The strength of OER motion and ACEO-caused orbital movement of particle chains can be adjusted by changing the frequency of alternating current (AC voltage. This non-contact method has the potential for spatially regulating the posture, orientation and position of microparticle chains.

  11. Interface Engineering and Morphology Study of Thin Film Organic-Inorganic Halide Perovskite Optoelectronic Devices

    Science.gov (United States)

    Meng, Lei

    significantly improved compared with cells made with organic layers. Degradation mechanisms were investigated and important guidelines were derived for future device design with a view to achieving both highly efficient and stable solar devices. Organometal halide based perovskite material has great optoelectronic proprieties, for example, shallow traps, benign grain boundaries and high diffusion length. The perovskite LEDs show pure electroluminescence (EL) with narrow full width at half maximum (FWHM), which is an advantage for display, lighting or lasing applications. In chapter five, perovskite LEDs are demonstrated employing solution processed charge injection layers with a quantum efficiency of 1.16% with a very low driving voltage.

  12. Granulometric composition study of mineral resources using opto-electronic devices and Elsieve software system

    Directory of Open Access Journals (Sweden)

    Kaminski Stanislaw

    2016-01-01

    Full Text Available The use of mechanical sieves has a great impact on measurement results because occurrence of anisometric particles causes undercounting the average size. Such errors can be avoided by using opto-electronic measuring devices that enable measurement of particles from 10 μm up to a few dozen millimetres in size. The results of measurement of each particle size fraction are summed up proportionally to its weight with the use of Elsieve software system and for every type of material particle-size distribution can be obtained. The software allows further statistical interpretation of the results. Beam of infrared radiation identifies size of particles and counts them precisely. Every particle is represented by an electronic impulse proportional to its size. Measurement of particles in aqueous suspension that replaces the hydrometer method can be carried out by using the IPS L analyser (range from 0.2 to 600 μm. The IPS UA analyser (range from 0.5 to 2000 μm is designed for measurement in the air. An ultrasonic adapter enables performing measurements of moist and aggregated particles from 0.5 to 1000 μm. The construction and software system allow to determine second dimension of the particle, its shape coefficient and specific surface area. The AWK 3D analyser (range from 0.2 to 31.5 mm is devoted to measurement of various powdery materials with subsequent determination of particle shape. The AWK B analyser (range from 1 to 130 mm measures materials of thick granulation and shape of the grains. The presented method of measurement repeatedly accelerates and facilitates study of granulometric composition.

  13. Investigation of Emerging Materials for Optoelectronic Devices Based on III-Nitrides

    KAUST Repository

    Muhammed, Mufasila Mumthaz

    2018-03-11

    III-nitride direct bandgap semiconductors have attracted significant research interest due to their outstanding potential for modern optoelectronic and electronic applications. However, the high cost of III-nitride devices, along with low performance due to dislocation defects, remains an obstacle to their further improvement. In this dissertation, I present a significant enhancement of III-nitride devices based on emerging materials. A promising substrate, (-201)-oriented β-Ga2O3 with unique properties that combine high transparency and conductivity, is used for the first time in the development of high-quality vertical III-nitride devices, which can be cost-effective for large-scale production. In addition, hybridizing GaN with emerging materials, mainly perovskite, is shown to extend the functionality of III-nitride applications. As a part of this investigation, high-performance and high-responsivity fast perovskite/GaN-based UV-visible broadband photodetectors were developed. State-of-the-art GaN epilayers grown on (-201)-oriented β-Ga2O3 using AlN and GaN buffer layers are discussed, and their high optical quality without using growth enhancement techniques is demonstrated. In particular, a low lattice mismatch (⁓4.7%) between GaN and the substrate results in a low density of dislocations ~4.8Å~107 cm−2. To demonstrates the effect of (-201)-oriented β-Ga2O3 substrate on the quality of III-nitride alloys, high-quality ternary alloy InxGa1−xN film is studied, followed by the growth of high quality InxGa1−xN/GaN single and multiple quantum wells (QWs). The optical characterization and carrier dynamics by photoluminescence (PL) and time-resolved PL measurements were subsequently performed. Lastly, to investigate the performance of a vertical emitting device based on InGaN/GaN multiple QWs grown on (-201)-oriented β-Ga2O3 substrate, high-efficiency vertical-injection emitting device is developed and extensively investigated. The conductive nature of

  14. Synthesis and optoelectronic properties of oxadiazole-functionalized iridium complexes in the poly(vinylcarbazole)-hosted devices

    International Nuclear Information System (INIS)

    Wu Zhonglian; Luo Cuiping; Jiang Changyun; Zhu Meixiang; Cao, Yong; Zhu Weiguo

    2008-01-01

    A class of oxadiazole-functionalized iridium complexes was used as phosphor emitters in poly (vinylcarbazole)-hosted devices. Efficient green electrophosphorescences were achieved in the devices with a maximum luminance efficiency of 9.3 cd/A at 10.6 mA/cm 2 and brightness of 3882 cd/m 2 at 92.1 mA/cm 2 . More importantly, the iridium complexes-doped devices exhibited a low turn-on voltage of 7.0 V and an applied voltage of 9.2 V at 500 cd/m 2 . The good optoelectronic properties of the complexes were attributed to the enhanced electron-injection and transport properties resulting from the effect of oxadiazole ligands in the complexes

  15. Integrated silicon optoelectronics

    CERN Document Server

    Zimmermann, Horst

    2000-01-01

    'Integrated Silicon Optoelectronics'assembles optoelectronics and microelectronics The book concentrates on silicon as the major basis of modern semiconductor devices and circuits Starting from the basics of optical emission and absorption and from the device physics of photodetectors, the aspects of the integration of photodetectors in modern bipolar, CMOS, and BiCMOS technologies are discussed Detailed descriptions of fabrication technologies and applications of optoelectronic integrated circuits are included The book, furthermore, contains a review of the state of research on eagerly expected silicon light emitters In order to cover the topic of the book comprehensively, integrated waveguides, gratings, and optoelectronic power devices are included in addition Numerous elaborate illustrations promote an easy comprehension 'Integrated Silicon Optoelectronics'will be of value to engineers, physicists, and scientists in industry and at universities The book is also recommendable for graduate students speciali...

  16. Optoelectronics circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Optoelectronics Circuits Manual covers the basic principles and characteristics of the best known types of optoelectronic devices, as well as the practical applications of many of these optoelectronic devices. The book describes LED display circuits and LED dot- and bar-graph circuits and discusses the applications of seven-segment displays, light-sensitive devices, optocouplers, and a variety of brightness control techniques. The text also tackles infrared light-beam alarms and multichannel remote control systems. The book provides practical user information and circuitry and illustrations.

  17. Tailoring uniform gold nanoparticle arrays and nanoporous films for next-generation optoelectronic devices

    Science.gov (United States)

    Farid, Sidra; Kuljic, Rade; Poduri, Shripriya; Dutta, Mitra; Darling, Seth B.

    2018-06-01

    High-density arrays of gold nanodots and nanoholes on indium tin oxide (ITO)-coated glass surfaces are fabricated using a nanoporous template fabricated by the self-assembly of diblock copolymers of poly (styrene-block-methyl methacrylate) (PS-b-PMMA) structures. By balancing the interfacial interactions between the polymer blocks and the substrate using random copolymer, cylindrical block copolymer microdomains oriented perpendicular to the plane of the substrate have been obtained. Nanoporous PS films are created by selectively etching PMMA cylinders, a straightforward route to form highly ordered nanoscale porous films. Deposition of gold on the template followed by lift off and sonication leaves a highly dense array of gold nanodots. These materials can serve as templates for the vapor-liquid-solid (VLS) growth of semiconductor nanorod arrays for next generation hybrid optoelectronic applications.

  18. Understanding and removing surface states limiting charge transport in TiO2 nanowire arrays for enhanced optoelectronic device performance.

    Science.gov (United States)

    Sheng, Xia; Chen, Liping; Xu, Tao; Zhu, Kai; Feng, Xinjian

    2016-03-01

    Charge transport within electrode materials plays a key role in determining the optoelectronic device performance. Aligned single-crystal TiO 2 nanowire arrays offer an ideal electron transport path and are expected to have higher electron mobility. Unfortunately, their transport is found not to be superior to that in nanoparticle films. Here we show that the low electron transport in rutile TiO 2 nanowires is mainly caused by surface traps in relatively deep energy levels, which cannot be removed by conventional approaches, such as oxygen annealing treatment. Moreover, we demonstrate an effective wet-chemistry approach to minimize these trap states, leading to over 20-fold enhancement in electron diffusion coefficient and 62% improvement in solar cell performance. On the basis of our results, the potential of TiO 2 NWs can be developed and well-utilized, which is significantly important for their practical applications.

  19. Electronic Processes at Organic−Organic Interfaces: Insight from Modeling and Implications for Opto-electronic Devices

    KAUST Repository

    Beljonne, David

    2011-02-08

    We report on the recent progress achieved in modeling the electronic processes that take place at interfaces between π-conjugated materials in organic opto-electronic devices. First, we provide a critical overview of the current computational techniques used to assess the morphology of organic: organic heterojunctions; we highlight the compromises that are necessary to handle large systems and multiple time scales while preserving the atomistic details required for subsequent computations of the electronic and optical properties. We then review some recent theoretical advances in describing the ground-state electronic structure at heterojunctions between donor and acceptor materials and highlight the role played by charge-transfer and long-range polarization effects. Finally, we discuss the modeling of the excited-state electronic structure at organic:organic interfaces, which is a key aspect in the understanding of the dynamics of photoinduced electron-transfer processes. © 2010 American Chemical Society.

  20. Organic optoelectronic materials

    CERN Document Server

    Li, Yongfang

    2015-01-01

    This volume reviews the latest trends in organic optoelectronic materials. Each comprehensive chapter allows graduate students and newcomers to the field to grasp the basics, whilst also ensuring that they have the most up-to-date overview of the latest research. Topics include: organic conductors and semiconductors; conducting polymers and conjugated polymer semiconductors, as well as their applications in organic field-effect-transistors; organic light-emitting diodes; and organic photovoltaics and transparent conducting electrodes. The molecular structures, synthesis methods, physicochemical and optoelectronic properties of the organic optoelectronic materials are also introduced and described in detail. The authors also elucidate the structures and working mechanisms of organic optoelectronic devices and outline fundamental scientific problems and future research directions. This volume is invaluable to all those interested in organic optoelectronic materials.

  1. Co-deposition methods for the fabrication of organic optoelectronic devices

    Science.gov (United States)

    Thompson, Mark E.; Liu, Zhiwei; Wu, Chao

    2016-09-06

    A method for fabricating an OLED by preparing phosphorescent metal complexes in situ is provided. In particular, the method simultaneously synthesizes and deposits copper (I) complexes in an organic light emitting device. Devices comprising such complexes may provide improved photoluminescent and electroluminescent properties.

  2. Temperature-Dependent Electric Field Poling Effects in CH3NH3PbI3 Optoelectronic Devices.

    Science.gov (United States)

    Zhang, Chuang; Sun, Dali; Liu, Xiaojie; Sheng, Chuan-Xiang; Vardeny, Zeev Valy

    2017-04-06

    Organo-lead halide perovskites show excellent optoelectronic properties; however, the unexpected inconsistency in forward-backward I-V characteristics remains a problem for fabricating solar panels. Here we have investigated the reasons behind this "hysteresis" by following the changes in photocurrent and photoluminescence under electric field poling in transverse CH 3 NH 3 PbI 3 -based devices from 300 to 10 K. We found that the hysteresis disappears at cryogenic temperatures, indicating the "freeze-out" of the ionic diffusion contribution. When the same device is cooled under continuous poling, the built-in electric field from ion accumulation brings significant photovoltaic effect even at 10 K. From the change of photoluminescence upon polling, we found a second dipole-related mechanism which enhances radiative recombination upon the alignment of the organic cations. The ionic origin of hysteresis was also verified by applying a magnetic field to affect the ion diffusion. These findings reveal the coexistence of ionic and dipole-related mechanisms for the hysteresis in hybrid perovskites.

  3. Ligand removal and photo-activation of CsPbBr3 quantum dots for enhanced optoelectronic devices.

    Science.gov (United States)

    Moyen, Eric; Kanwat, Anil; Cho, Sinyoung; Jun, Haeyeon; Aad, Roy; Jang, Jin

    2018-05-10

    Perovskite quantum dots have recently emerged as a promising light source for optoelectronic applications. However, integrating them into devices while preserving their outstanding optical properties remains challenging. Due to their ionic nature, perovskite quantum dots are extremely sensitive and degrade on applying the simplest processes. To maintain their colloidal stability, they are surrounded by organic ligands; these prevent efficient charge carrier injection in devices and have to be removed. Here we report on a simple method, where a moderate thermal process followed by exposure to UV in air can efficiently remove ligands and increase the photo-luminescence of the room temperature synthesized perovskite quantum dot thin films. Annealing is accompanied by a red shift of the emission wavelength, usually attributed to the coalescence and irreversible degradation of the quantum dots. We show that it is actually related to the relaxation of the quantum dots upon the ligand removal, without the creation of non-radiative recombining defects. The quantum dot surface, as devoid of ligands, is subsequently photo-oxidized and smoothened upon exposure to UV in air, which drastically enhances their photo-luminescence. This adequate combination of treatments improves by more than an order of magnitude the performances of perovskite quantum dot light emitting diodes.

  4. Study of various n-type organic semiconductors on ultraviolet detective and electroluminescent properties of optoelectronic integrated device

    Science.gov (United States)

    Deng, Chaoxu; Shao, Bingyao; Zhao, Dan; Zhou, Dianli; Yu, Junsheng

    2017-11-01

    Organic optoelectronic integrated device (OID) with both ultraviolet (UV) detective and electroluminescent (EL) properties was fabricated by using a thermally activated delayed fluorescence (TADF) semiconductor of (4s, 6s)-2,4,5,6-tetra(9H-carbazol-9-yl)isophthalonitrile (4CzIPN) as an emitter. The effect of five kinds of n-type organic semiconductors (OSCs) on the enhancement of UV detective and EL properties of OID was systematically studied. The result shows that two orders of magnitude in UV detectivity from 109 to 1011 Jones and 3.3 folds of luminance from 2499 to 8233 cd m-2 could be achieved. The result shows that not only the difference of lowest unoccupied molecular orbital (LUMO) between active layer and OSC but also the variety of electron mobility have a significant effect on the UV detective and EL performance through adjusting electron injection/transport. Additionally, the optimized OSC thickness is beneficial to confine the leaking of holes from the active layer to cathode, leading to the decrease of dark current for high detective performance. This work provides a useful method on broadening OSC material selection and device architecture construction for the realization of high performance OID.

  5. Electrochemistry, polymers and opto-electronic devices: a combination with a future

    Directory of Open Access Journals (Sweden)

    De Paoli Marco-A.

    2002-01-01

    Full Text Available Electrochemistry came into life with the invention of the pile, by Volta in 1800. He combined different metal discs with a piece of tissue, swollen with an aqueous salt solution. The so-called Pila di Volta used a polymer for the first time in an electrochemical device and can be seen as a powerful idea to create new devices. Recently, polymers became an alternative to make thin and flexible devices. Thus, we find transparent plastic electrodes based on poly(ethylene terephtalate coated with a transition metal oxide. There are also polymer electrolytes based on complexes of inorganic salts and poly(ethylene oxide derivatives, with reasonable ionic conductivity in the absence of solvents. Finally, the electroactive polymers are efficient substitutes for the inorganic semiconductors because they can be synthetically tailored to produce the desired electronic answer. Combining these materials it is possible to assemble different types of electro-optical devices, like electrochromic, photoelectrochemical and light-emitting electrochemical cells.

  6. Investigation of Emerging Materials for Optoelectronic Devices Based on III-Nitrides

    KAUST Repository

    Mumthaz Muhammed, Mufasila

    2018-01-01

    performance due to dislocation defects, remains an obstacle to their further improvement. In this dissertation, I present a significant enhancement of III-nitride devices based on emerging materials. A promising substrate, (-201)-oriented β-Ga2O3 with unique

  7. Growth and Characterisation of GaAs/AlGaAs Core-shell Nanowires for Optoelectronic Device Applications

    Science.gov (United States)

    Jiang, Nian

    III-V semiconductor nanowires have been investigated as key components for future electronic and optoelectronic devices and systems due to their direct band gap and high electron mobility. Amongst the III-V semiconductors, the planar GaAs material system has been extensively studied and used in industries. Accordingly, GaAs nanowires are the prime candidates for nano-scale devices. However, the electronic performance of GaAs nanowires has yet to match that of state-of-the-art planar GaAs devices. The present deficiency of GaAs nanowires is typically attributed to the large surface-to- volume ratio and the tendency for non-radiative recombination centres to form at the surface. The favoured solution of this problem is by coating GaAs nanowires with AlGaAs shells, which replaces the GaAs surface with GaAs/AlGaAs interface. This thesis presents a systematic study of GaAs/AlGaAs core-shell nanowires grown by metal organic chemical vapour deposition (MOCVD), including understanding the growth, and characterisation of their structural and optical properties. The structures of the nanowires were mainly studied by scanning electron microscopy and transmis- sion electron microscopy (TEM). A procedure of microtomy was developed to prepare the cross-sectional samples for the TEM studies. The optical properties were charac- terised by photoluminescence (PL) spectroscopy. Carrier lifetimes were measured by time-resolved PL. The growth of AlGaAs shell was optimised to obtain the best optical properties, e.g. the strongest PL emission and the longest minority carrier lifetimes. (Abstract shortened by ProQuest.).

  8. A hybrid organic-inorganic electrode for enhanced charge injection or collection in organic optoelectronic devices

    International Nuclear Information System (INIS)

    Yilmaz, Omer F; Chaudhary, Sumit; Ozkan, Mihrimah

    2006-01-01

    Here we report a novel hybrid organic-inorganic anode for organic light-emitting diodes (LEDs) and photovoltaic (PV) cells. This hybrid anode structure is realized from a composite of poly(3,4-ethylene dioxythiophene) doped with polystyrenesulfonic acid (PEDOT:PSS) and indium tin oxide (ITO) nanoparticles. Owing to the phase separation, this anodic structure leads to a graded work function from patterned ITO to the photoactive polymer, which in turn reduces the barrier height for holes by ∼70%. The resulting devices based on this design show up to 67% reduction in turn-on voltage (for polymer LEDs) and up to 40% increase in short-circuit current and power conversion efficiency (for PV cells). Current-voltage characteristics, Fowler-Nordheim analysis, SEM imaging and energy band diagram analysis are employed to characterize the improved performance of our devices. The reported approach is expected to be immensely useful for the molecular design of next-generation efficient organic devices

  9. Tunable Schottky barrier and high responsivity in graphene/Si-nanotip optoelectronic device

    Science.gov (United States)

    Di Bartolomeo, Antonio; Giubileo, Filippo; Luongo, Giuseppe; Iemmo, Laura; Martucciello, Nadia; Niu, Gang; Fraschke, Mirko; Skibitzki, Oliver; Schroeder, Thomas; Lupina, Grzegorz

    2017-03-01

    We demonstrate tunable Schottky barrier height and record photo-responsivity in a new-concept device made of a single-layer CVD graphene transferred onto a matrix of nanotips patterned on n-type Si wafer. The original layout, where nano-sized graphene/Si heterojunctions alternate to graphene areas exposed to the electric field of the Si substrate, which acts both as diode cathode and transistor gate, results in a two-terminal barristor with single-bias control of the Schottky barrier. The nanotip patterning favors light absorption, and the enhancement of the electric field at the tip apex improves photo-charge separation and enables internal gain by impact ionization. These features render the device a photodetector with responsivity (3 {{A}} {{{W}}}-1 for white LED light at 3 {{mW}} {{{cm}}}-2 intensity) almost an order of magnitude higher than commercial photodiodes. We extensively characterize the voltage and the temperature dependence of the device parameters, and prove that the multi-junction approach does not add extra-inhomogeneity to the Schottky barrier height distribution. We also introduce a new phenomenological graphene/semiconductor diode equation, which well describes the experimental I-V characteristics both in forward and reverse bias.

  10. Optoelectronic stereoscopic device for diagnostics, treatment, and developing of binocular vision

    Science.gov (United States)

    Pautova, Larisa; Elkhov, Victor A.; Ovechkis, Yuri N.

    2003-08-01

    Operation of the device is based on alternative generation of pictures for left and right eyes on the monitor screen. Controller gives pulses on LCG so that shutter for left or right eye opens synchronously with pictures. The device provides frequency of switching more than 100 Hz, and that is why the flickering is absent. Thus, a separate demonstration of images to the left eye or to the right one in turn is obtained for patients being unaware and creates the conditions of binocular perception clsoe to natural ones without any additional separation of vision fields. LC-cell transfer characteristic coodination with time parameters of monitor screen has enabled to improve stereo image quality. Complicated problem of computer stereo images with LC-glasses is so called 'ghosts' - noise images that come to blocked eye. We reduced its influence by adapting stereo images to phosphor and LC-cells characteristics. The device is intended for diagnostics and treatment of stabismus, amblyopia and other binocular and stereoscopic vision impairments, for cultivating, training and developing of stereoscopic vision, for measurements of horizontal and vertical phoria, phusion reserves, the stereovision acuity and some else, for fixing central scotoma borders, as well as suppression scotoma in strabismus too.

  11. Structural and optical properties of silicon rich oxide films in graded-stoichiometric multilayers for optoelectronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Palacios-Huerta, L.; Aceves-Mijares, M. [Electronics Department, INAOE, Apdo. 51, Puebla, Pue. 72000, México (Mexico); Cabañas-Tay, S. A.; Cardona-Castro, M. A.; Morales-Sánchez, A., E-mail: alfredo.morales@cimav.edu.mx [Centro de Investigación en Materiales Avanzados S.C., Unidad Monterrey-PIIT, Apodaca, NL 66628, México (Mexico); Domínguez-Horna, C. [Instituto de Microelectrónica de Barcelona, IMB-CNM (CSIC), Bellaterra 08193, Barcelona (Spain)

    2016-07-18

    Silicon nanocrystals (Si-ncs) are excellent candidates for the development of optoelectronic devices. Nevertheless, different strategies are still necessary to enhance their photo and electroluminescent properties by controlling their structural and compositional properties. In this work, the effect of the stoichiometry and structure on the optical properties of silicon rich oxide (SRO) films in a multilayered (ML) structure is studied. SRO MLs with silicon excess gradually increased towards the top and bottom and towards the center of the ML produced through the variation of the stoichiometry in each SRO layer were fabricated and confirmed by X-ray photoelectron spectroscopy. Si-ncs with three main sizes were observed by a transmission electron microscope, in agreement with the stoichiometric profile of each SRO layer. The presence of the three sized Si-ncs and some oxygen related defects enhances intense violet/blue and red photoluminescence (PL) bands. The SRO MLs were super-enriched with additional excess silicon by Si{sup +} implantation, which enhanced the PL intensity. Oxygen-related defects and small Si-ncs (<2 nm) are mostly generated during ion implantation enhancing the violet/blue band to become comparable to the red band. The structural, compositional, and luminescent characteristics of the multilayers are the result of the contribution of the individual characteristics of each layer.

  12. Effects of Long-Term Static Bending Deformation on a Barrier Thin Film for Flexible Organic Optoelectronic Devices

    Directory of Open Access Journals (Sweden)

    Hung-I Lu

    2018-03-01

    Full Text Available The objective of this study is to investigate the effect of long-term static bending on the encapsulation properties of a commercial barrier thin film for flexible optoelectronic devices. Encapsulation properties of the barrier film are evaluated under long-term static bending at various radii of curvature. Experimental results reveal that no significantly detrimental effect on the water vapor transmission rate (WVTR at 40 °C and 90% RH is found for compressive bending up to 1000 h and for tensile bending up to 100 h with a radius of curvature of 5 mm or larger. However, WVTR of the barrier thin film is significantly increased and cracks are found in the barrier film when subjected to tensile bending of a radius of 10 mm or 5 mm for 1000 h. The expected WVTR of the given barrier thin film is numerically computed using a three-dimensional (3D finite element model. Numerical results indicate that, with the presence of cracks in the barrier thin film, the WVTR increases for an apparent increase in moisture entrances. The WVTR calculated by the 3D cracking model concurs with the experimental results.

  13. Study of epitaxial lateral overgrowth of GaN for application in the fabrication of optoelectronic devices

    Science.gov (United States)

    Berry Ann, N. J.; Rodak, L. E.; Kasarla, Kalyan; Yang, Nanying; Korakakis, D.

    2005-10-01

    In this research effort, epitaxial lateral overgrowth (ELOG) of GaN on sapphire was performed by low-pressure metalorganic chemical vapor deposition (MOCVD) in a horizontal reactor. All ELOG growths were stopped prior to complete coalescence, and the resulting cross-sections were characterized by scanning electron microscopy (SEM). Both vertical {1120} and inclined sidewalls were observed. Inclined {112n}sidewalls of various angles (n 2-2.2) were found as previously reported in the literature1. Both one-step and two-step ELOG processes were used to control the overgrowth geometry. It was confirmed that sidewall formation and growth rates are closely correlated with multiple parameters including temperature and V/III ratio1. It was also found that substrate rotation greatly influences sidewall evolution and vertical growth rate. A conceptual model was begun to completely describe the ELOG process in a horizontal reactor. It is speculated that the different sidewalls observed as a function of substrate orientation result from variation in the local V/III ratio. Once developed, the final model will be used to control the sidewalls in the growth of ELOG structures for the fabrication of novel optoelectronic devices.

  14. Latest developments in GaN-based quantum devices for infrared optoelectronics

    OpenAIRE

    Monroy, Eva; Guillot, Fabien; Leconte, Sylvain; Nevou, Laurent; Doyennette, Laeticia; Tchernycheva, Maria; Julien, François H.; Baumann, Esther; Giorgetta, Fabrizio R.; Hofstetter, Daniel

    2011-01-01

    In this work, we summarize the latest progress in intersubband devices based on GaN/AlN nanostructures for operation in the near-infrared. We first discuss the growth and characterization of ultra-thin GaN/AlN quantum well and quantum dot superlattices by plasma-assisted molecular-beam epitaxy. Then, we present the performance of nitride-based infrared photodetectors and electro-optical modulators operating at 1.55 μm. Finally, we discuss the progress towards intersubband light emitters, incl...

  15. Enhancement of photocurrent extraction and electron injection in dual-functional CH3NH3PbBr3 perovskite-based optoelectronic devices via interfacial engineering

    Science.gov (United States)

    Tsai, Chia-Lung; Lu, Yi-Chen; Hsiung Chang, Sheng

    2018-07-01

    Photocurrent extraction and electron injection in CH3NH3PbBr3 (MAPbBr3) perovskite-based optoelectronic devices are both significantly increased by improving the contact at the PCBM/MAPbBr3 interface with an extended solvent annealing (ESA) process. Photoluminescence quenching and x-ray diffraction experiments show that the ESA not only improves the contact at the PCBM/MAPbBr3 interface but also increases the crystallinity of the MAPbBr3 thin films. The optimized dual-functional PCBM-MAPbBr3 heterojunction based optoelectronic device has a high power conversion efficiency of 4.08% and a bright visible luminescence of 1509 cd m‑2. In addition, the modulation speed of the MAPbBr3 based light-emitting diodes is larger than 14 MHz, which indicates that the defect density in the MAPbBr3 thin film can be effectively reduced by using the ESA process.

  16. Temperature and carrier-density dependence of Auger and radiative recombination in nitride optoelectronic devices

    International Nuclear Information System (INIS)

    Kioupakis, Emmanouil; Yan, Qimin; Steiauf, Daniel; Van de Walle, Chris G

    2013-01-01

    Nitride light-emitting diodes are a promising solution for efficient solid-state lighting, but their performance at high power is affected by the efficiency-droop problem. Previous experimental and theoretical work has identified Auger recombination, a three-particle nonradiative carrier recombination mechanism, as the likely cause of the droop. In this work, we use first-principles calculations to elucidate the dependence of the radiative and Auger recombination rates on temperature, carrier density and quantum-well confinement. Our calculated data for the temperature dependence of the recombination coefficients are in good agreement with experiment and provide further validation on the role of Auger recombination in the efficiency reduction. Polarization fields and phase-space filling negatively impact device efficiency because they increase the operating carrier density at a given current density and increase the fraction of carriers lost to Auger recombination. (paper)

  17. Cubic boron nitride (cBN) - A new material for advanced optoelectronic devices. Properties and perspectives

    International Nuclear Information System (INIS)

    Nistor, S.V.; Nistor, L.C.; Dinca, G.

    2001-01-01

    Cubic boron nitride (cBN) exhibits, besides exceptional thermal and mechanical properties similar to diamond, an excellent ability to be n or p doped, which makes it a strong candidate for advanced, high - temperature optical and microelectronic devices. Despite its outstanding characteristics, there are quite a few reports concerning the physical properties of cBN. This is partly due to the absence of natural cBN gems and the extreme difficulties in producing enough large (mm 3 sized) single crystals, or single phase thin films, for physical characterization. The state of the art knowledge concerning the basic properties of crystalline cBN, as well as our recent results of microstructure and defect properties studies will be presented. (authors)

  18. Single-photon superradiance and cooperative Lamb shift in an optoelectronic device (Conference Presentation)

    Science.gov (United States)

    Sirtori, Carlo

    2017-02-01

    Superradiance is one of the many fascinating phenomena predicted by quantum electrodynamics that have first been experimentally demonstrated in atomic systems and more recently in condensed matter systems like quantum dots, superconducting q-bits, cyclotron transitions and plasma oscillations in quantum wells (QWs). It occurs when a dense collection of N identical two-level emitters are phased via the exchange of photons, giving rise to enhanced light-matter interaction, hence to a faster emission rate. Of great interest is the regime where the ensemble interacts with one photon only and therefore all of the atoms, but one, are in the ground state. In this case the quantum superposition of all possible configurations produces a symmetric state that decays radiatively with a rate N times larger than that of the individual oscillators. This phenomenon, called single photon superradiance, results from the exchange of real photons among the N emitters. Yet, to single photon superradiance is also associated another collective effect that renormalizes the emission frequency, known as cooperative Lamb shift. In this work, we show that single photon superradiance and cooperative Lamb shift can be engineered in a semiconductor device by coupling spatially separated plasma resonances arising from the collective motion of confined electrons in QWs. These resonances hold a giant dipole along the growth direction z and have no mutual Coulomb coupling. They thus behave as a collection of macro-atoms on different positions along the z axis. Our device is therefore a test bench to simulate the low excitation regime of quantum electrodynamics.

  19. Optoelectronic Mounting Structure

    Science.gov (United States)

    Anderson, Gene R.; Armendariz, Marcelino G.; Baca, Johnny R. F.; Bryan, Robert P.; Carson, Richard F.; Chu, Dahwey; Duckett, III, Edwin B.; McCormick, Frederick B.; Peterson, David W.; Peterson, Gary D.; Reber, Cathleen A.; Reysen, Bill H.

    2004-10-05

    An optoelectronic mounting structure is provided that may be used in conjunction with an optical transmitter, receiver or transceiver module. The mounting structure may be a flexible printed circuit board. Thermal vias or heat pipes in the head region may transmit heat from the mounting structure to the heat spreader. The heat spreader may provide mechanical rigidity or stiffness to the heat region. In another embodiment, an electrical contact and ground plane may pass along a surface of the head region so as to provide an electrical contact path to the optoelectronic devices and limit electromagnetic interference. In yet another embodiment, a window may be formed in the head region of the mounting structure so as to provide access to the heat spreader. Optoelectronic devices may be adapted to the heat spreader in such a manner that the devices are accessible through the window in the mounting structure.

  20. Spectroscopic investigation of the chemical and electronic properties of chalcogenide materials for thin-film optoelectronic devices

    Science.gov (United States)

    Horsley, Kimberly Anne

    Chalcogen-based materials are at the forefront of technologies for sustainable energy production. This progress has come only from decades of research, and further investigation is needed to continue improvement of these materials. For this dissertation, a number of chalcogenide systems were studied, which have applications in optoelectronic devices, such as LEDs and Photovoltaics. The systems studied include Cu(In,Ga)Se2 (CIGSe) and CuInSe 2 (CISe) thin-film absorbers, CdTe-based photovoltaic structures, and CdTe-ZnO nanocomposite materials. For each project, a sample set was prepared through collaboration with outside institutions, and a suite of spectroscopy techniques was employed to answer specific questions about the system. These techniques enabled the investigation of the chemical and electronic structure of the materials, both at the surface and towards the bulk. CdS/Cu(In,Ga)Se2 thin-films produced from the roll-to-roll, ambient pressure, Nanosolar industrial line were studied. While record-breaking efficiency cells are usually prepared in high-vacuum (HV) or ultra-high vacuum (UHV) environments, these samples demonstrate competitive mass-production efficiency without the high-cost deposition environment. We found relatively low levels of C contaminants, limited Na and Se oxidation, and a S-Se intermixing at the CdS/CIGSe interface. The surface band gap compared closely to previously investigated CIGSe thin-films deposited under vacuum, illustrating that roll-to-roll processing is a promising and less-expensive alternative for solar cell production. An alternative deposition process for CuInSe2 was also studied, in collaboration with the University of Luxembourg. CuInSe2 absorbers were prepared with varying Cu content and surface treatments to investigate the potential to produce an absorber with a Cu-rich bulk and Cu-poor surface. This is desired to combine the bulk characteristics of reduced defects and larger grains in Cu-rich films, while maintaining

  1. Modeling of Optoelectronic Devices

    Science.gov (United States)

    Li, Jian-Zhong; Woo, Alex C. (Technical Monitor)

    2000-01-01

    Ultrafast modulation of semiconductor quantum well (QW) laser is of technological importance for information technology. Improvement by order(s) of magnitude in data transfer rate is possible as terahertz (THz) radiation is available for heating the laser at picosecond time scale. Optical gain modulation in the QW is achieved via temperature modulation of electron-hole plasma (EHP). Applications include free-space THz communication, optical switching, and pulse generation. The EHP in the semiconductor QW is described with a two-band model. Semiconductor Bloch equations with many-body effects are used to derive a hydrodynamical model for the active QW region. Because of ultrafast carrier-carrier scatterings in the order of 50 fs, EHP follows quasiequilibrium Fermi-Dirac distributions and THz field interacts incoherently with it. Carrier-longitudinal optical (LO) phonon scatterings and coherent laser-EHP interaction are treated microscopically in our physical model. A set of hydrodynamical equations for plasma density, temperature, and laser envelop amplitude are derived and Runge-Kutta method is adopted for numerical simulation. A typical 8 nm GaAs/Al(0.3)Ga(0.7) As single QW at 300 K is used. Additional information is contained in the original extended abstract.

  2. Semiconductor opto-electronics

    CERN Document Server

    Moss, TS; Ellis, B

    1972-01-01

    Semiconductor Opto-Electronics focuses on opto-electronics, covering the basic physical phenomena and device behavior that arise from the interaction between electromagnetic radiation and electrons in a solid. The first nine chapters of this book are devoted to theoretical topics, discussing the interaction of electromagnetic waves with solids, dispersion theory and absorption processes, magneto-optical effects, and non-linear phenomena. Theories of photo-effects and photo-detectors are treated in detail, including the theories of radiation generation and the behavior of semiconductor lasers a

  3. P-type SnO thin films and SnO/ZnO heterostructures for all-oxide electronic and optoelectronic device applications

    Energy Technology Data Exchange (ETDEWEB)

    Saji, Kachirayil J. [Nanostructured Materials Research Laboratory, Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112 (United States); Department of Physics, Govt. Victoria College, University of Calicut, Palakkad 678 001 (India); Venkata Subbaiah, Y.P. [Nanostructured Materials Research Laboratory, Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112 (United States); Department of Physics, Yogi Vemana University, Kadapa, Andhra Pradesh 516003 (India); Tian, Kun [Nanostructured Materials Research Laboratory, Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112 (United States); Tiwari, Ashutosh, E-mail: tiwari@eng.utah.edu [Nanostructured Materials Research Laboratory, Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112 (United States)

    2016-04-30

    Tin monoxide (SnO) is considered as one of the most important p-type oxides available to date. Thin films of SnO have been reported to possess both an indirect bandgap (~ 0.7 eV) and a direct bandgap (~ 2.8 eV) with quite high hole mobility (~ 7 cm{sup 2}/Vs) values. Moreover, the hole density in these films can be tuned from 10{sup 15}–10{sup 19} cm{sup −3} just by controlling the thin film deposition parameters. Because of the above attributes, SnO thin films offer great potential for fabricating modern electronic and optoelectronic devices. In this article, we are reviewing the most recent developments in this field and also presenting some of our own results on SnO thin films grown by pulsed laser deposition technique. We have also proposed a p–n heterostructure comprising of p-type SnO and n-type ZnO which can pave way for realizing next-generation, all-oxide transparent electronic devices. - Highlights: • We reviewed recent developments on p-type SnO thin film research. • Discussed the optical and electrical properties of SnO thin films • Bipolar conduction in SnO is discussed. • Optoelectronic properties of SnO–ZnO composite system are discussed. • Proposed SnO–ZnO heterojunction band structure.

  4. Plasma vapor deposited n-indium tin oxide/p-copper indium oxide heterojunctions for optoelectronic device applications

    Science.gov (United States)

    Jaya, T. P.; Pradyumnan, P. P.

    2017-12-01

    Transparent crystalline n-indium tin oxide/p-copper indium oxide diode structures were fabricated on quartz substrates by plasma vapor deposition using radio frequency (RF) magnetron sputtering. The p-n heterojunction diodes were highly transparent in the visible region and exhibited rectifying current-voltage (I-V) characteristics with a good ideality factor. The sputter power during fabrication of the p-layer was found to have a profound effect on I-V characteristics, and the diode with the p-type layer deposited at a maximum power of 200 W exhibited the highest value of the diode ideality factor (η value) of 2.162, which suggests its potential use in optoelectronic applications. The ratio of forward current to reverse current exceeded 80 within the range of applied voltages of -1.5 to +1.5 V in all cases. The diode structure possessed an optical transmission of 60-70% in the visible region.

  5. Opto-electronic device for frequency standard generation and terahertz-range optical demodulation based on quantum interference

    Science.gov (United States)

    Georgiades, Nikos P.; Polzik, Eugene S.; Kimble, H. Jeff

    1999-02-02

    An opto-electronic system and technique for comparing laser frequencies with large frequency separations, establishing new frequency standards, and achieving phase-sensitive detection at ultra high frequencies. Light responsive materials with multiple energy levels suitable for multi-photon excitation are preferably used for nonlinear mixing via quantum interference of different excitation paths affecting a common energy level. Demodulation of a carrier with a demodulation frequency up to 100's THZ can be achieved for frequency comparison and phase-sensitive detection. A large number of materials can be used to cover a wide spectral range including the ultra violet, visible and near infrared regions. In particular, absolute frequency measurement in a spectrum from 1.25 .mu.m to 1.66 .mu.m for fiber optics can be accomplished with a nearly continuous frequency coverage.

  6. Terahertz optoelectronics in graphene

    International Nuclear Information System (INIS)

    Otsuji, Taiichi

    2016-01-01

    Graphene has attracted considerable attention due to its extraordinary carrier transport, optoelectronic, and plasmonic properties originated from its gapless and linear energy spectra enabling various functionalities with extremely high quantum efficiencies that could never be obtained in any existing materials. This paper reviews recent advances in graphene optoelectronics particularly focused on the physics and device functionalities in the terahertz (THz) electromagnetic spectral range. Optical response of graphene is characterized by its optical conductivity and nonequilibrium carrier energy relaxation dynamics, enabling amplification of THz radiation when it is optically or electrically pumped. Current-injection THz lasing has been realized very recently. Graphene plasmon polaritons can greatly enhance the THz light and graphene matter interaction, enabling giant enhancement in detector responsivity as well as amplifier/laser gain. Graphene-based van der Waals heterostructures could give more interesting and energy-efficient functionalities. (author)

  7. NASA Electronic Parts and Packaging (NEPP): Space Qualification Guidelines of Optoelectronic and Photonic Devices for Optical Communication Systems

    Science.gov (United States)

    Kim, Quiesup

    2001-01-01

    Key elements of space qualification of opto-electric and photonic optical devices were overviewed. Efforts were concentrated on the reliability concerns of the devices needed for potential applications in space environments. The ultimate goal for this effort is to gradually establish enough data to develop a space qualification plan of newly developed specific photonic parts using empirical and numerical models to assess the life-time and degradation of the devices for potential long term space missions.

  8. Enhanced Optoelectronic Performance of a Passivated Nanowire-Based Device: Key Information from Real-Space Imaging Using 4D Electron Microscopy

    KAUST Repository

    Khan, Jafar Iqbal

    2016-03-03

    Managing trap states and understanding their role in ultrafast charge-carrier dynamics, particularly at surface and interfaces, remains a major bottleneck preventing further advancements and commercial exploitation of nanowire (NW)-based devices. A key challenge is to selectively map such ultrafast dynamical processes on the surfaces of NWs, a capability so far out of reach of time-resolved laser techniques. Selective mapping of surface dynamics in real space and time can only be achieved by applying four-dimensional scanning ultrafast electron microscopy (4D S-UEM). Charge carrier dynamics are spatially and temporally visualized on the surface of InGaN NW arrays before and after surface passivation with octadecylthiol (ODT). The time-resolved secondary electron images clearly demonstrate that carrier recombination on the NW surface is significantly slowed down after ODT treatment. This observation is fully supported by enhancement of the performance of the light emitting device. Direct observation of surface dynamics provides a profound understanding of the photophysical mechanisms on materials\\' surfaces and enables the formulation of effective surface trap state management strategies for the next generation of high-performance NW-based optoelectronic devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Exfoliating and Dispersing Few-Layered Graphene in Low-Boiling-Point Organic Solvents towards Solution-Processed Optoelectronic Device Applications.

    Science.gov (United States)

    Zhang, Lu; Miao, Zhongshuo; Hao, Zhen; Liu, Jun

    2016-05-06

    With normal organic surfactants, graphene can only be dispersed in water and cannot be dispersed in low-boiling-point organic solvents, which hampers its application in solution-processed organic optoelectronic devices. Herein, we report the exfoliation of graphite into graphene in low-boiling-point organic solvents, for example, methanol and acetone, by using edge-carboxylated graphene quantum dots (ECGQD) as the surfactant. The great capability of ECGQD for graphene dispersion is due to its ultralarge π-conjugated unit that allows tight adhesion on the graphene surface through strong π-π interactions, its edge-carboxylated structure that diminishes the steric effects of the oxygen-containing functional groups on the basal plane of ECGQD, and its abundance of carboxylic acid groups for solubility. The graphene dispersion in methanol enables the application of graphene:ECGQD as a cathode interlayer in polymer solar cells (PSCs). Moreover, the PSC device performance of graphene:ECGQD is better than that of Ca, the state-of-the-art cathode interlayer material. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Slot-Die-Coated V2O5 as Hole Transport Layer for Flexible Organic Solar Cells and Optoelectronic Devices

    DEFF Research Database (Denmark)

    Beliatis, Michail; Helgesen, Martin; Garcia Valverde, Rafael

    2016-01-01

    Vanadium pentoxide has been proposed as a good alternative hole transport layer for improving device lifetime of organic photovoltaics. The article presents a study on the optimization of slot-die-coated vanadium oxide films produced with a roll coating machine with the aim of achieving scalable ...

  11. Reduced Graphene Oxide-Cadmium Zinc Sulfide Nanocomposite with Controlled Band Gap for Large-Area Thin-Film Optoelectronic Device Application

    Science.gov (United States)

    Ibrahim, Sk; Chakraborty, Koushik; Pal, Tanusri; Ghosh, Surajit

    2017-12-01

    Herein, we report the one pot single step solvothermal synthesis of reduced grapheme oxide-cadmium zinc sulfide (RGO-Cd0.5Zn0.5S) composite. The reduction in graphene oxide (GO), synthesis of Cd0.5Zn0.5S (mentioned as CdZnS in the text) nanorod and decoration of CdZnS nanorods onto RGO sheet were done simultaneously. The structural, morphological and optical properties were studied thoroughly by different techniques, such as XRD, TEM, UV-Vis and PL. The PL intensity of CdZnS nanorods quenches significantly after the attachment of RGO, which confirms photoinduced charge transformation from CdZnS nanorods to RGO sheet through the interface of RGO-CdZnS. An excellent photocurrent generation in RGO-CdZnS thin-film device has been observed under simulated solar light irradiation. The photocurrent as well as photosensitivity increases linearly with the solar light intensity for all the composites. Our study establishes that the synergistic effect of RGO and CdZnS in the composite is capable of getting promising applications in the field of optoelectronic devising.

  12. Application of CaCu3Ti4O12 based quadruple perovskites as a promising candidate for optoelectronic devices

    Science.gov (United States)

    Pal, Kamalesh; Jana, Rajkumar; Dey, Arka; Ray, Partha P.; Seikh, Md Motin; Gayen, Arup

    2018-05-01

    We report the synthesis of nanosized (40-50 nm) CaCu3-xMnxTi4-xMnxO12 (x = 0, 0.5 and 1) quadruple perovskite (QP) semiconductor via a modified combustion method for use as Schottky barrier diode (SBD) at the Al/QP junction. The fabricated SBD is analysed on the basis of thermionic emission theory to observe its quality and some important diode parameters. For insight analysis of charge transport mechanism through metal-semiconductor junction, theory of space charge limited currents is applied and discussed in the light of parameters like carrier concentration, mobility-lifetime product and diffusion length. The Mn-doped exhibit better device performance compared to parent material.

  13. Optoelectronic characterization of Eu3+ doped MLa2O4 (M = Sr, Ca, Mg nanophosphors for display devices

    Directory of Open Access Journals (Sweden)

    Devender Singh

    2015-12-01

    Full Text Available Eu3+ doped MLa2O4 (M = Mg, Ca, Sr nanophosphors were synthesized by a rapid facile gel combustion route. Luminescence properties of these prepared nanophosphors were analyzed by their excitation and emission spectra. The excitation spectrum consisted of some peaks in the 350–410 nm range due to the f–f transitions. The emission spectra of prepared nanophosphors had transitions of Eu3+ ions i.e. 5D0 → 7F0 (580 nm, 5D0 → 7F1 (594–596 nm, 5D0 → 7F2 (614–618, 628–629 nm, and 5D0 → 7F3 (650–651 nm. The main emission peak was observed at 614–618 nm of 5D0→7F2 transitions of Eu3+ ions. The enhancement in optical properties was observed when materials were reheated at higher temperatures. The nanostructural morphology was confirmed with scanning as well as transmission electron microscopy. The prepared materials were having size in the range of 10–50 nm. X-ray powder diffraction (XRD technique was used to determine the crystal structure and phase of the prepared phosphor materials. XRD measurements revealed that the crystallinity of MLa2O4 materials increased with increasing the sintering temperature. The prepared materials had bright red emitting optical properties that could be suitably applied in various display devices.

  14. Integrated optoelectronic oscillator.

    Science.gov (United States)

    Tang, Jian; Hao, Tengfei; Li, Wei; Domenech, David; Baños, Rocio; Muñoz, Pascual; Zhu, Ninghua; Capmany, José; Li, Ming

    2018-04-30

    With the rapid development of the modern communication systems, radar and wireless services, microwave signal with high-frequency, high-spectral-purity and frequency tunability as well as microwave generator with light weight, compact size, power-efficient and low cost are increasingly demanded. Integrated microwave photonics (IMWP) is regarded as a prospective way to meet these demands by hybridizing the microwave circuits and the photonics circuits on chip. In this article, we propose and experimentally demonstrate an integrated optoelectronic oscillator (IOEO). All of the devices needed in the optoelectronic oscillation loop circuit are monolithically integrated on chip within size of 5×6cm 2 . By tuning the injection current to 44 mA, the output frequency of the proposed IOEO is located at 7.30 GHz with phase noise value of -91 dBc/Hz@1MHz. When the injection current is increased to 65 mA, the output frequency can be changed to 8.87 GHz with phase noise value of -92 dBc/Hz@1MHz. Both of the oscillation frequency can be slightly tuned within 20 MHz around the center oscillation frequency by tuning the injection current. The method about improving the performance of IOEO is carefully discussed at the end of in this article.

  15. Structural, optical and morphological properties of post-growth calcined TiO{sub 2} nanopowder for opto-electronic device application: Ex-situ studies

    Energy Technology Data Exchange (ETDEWEB)

    Sathyaseelan, B., E-mail: bsseelan03@gmail.com [Dept of Physics, University College of Engineering Arni (A Constituent College of Anna University Chennai) Arni 632326, Tamil Nadu (India); Manikandan, E., E-mail: maniphysics@gmail.com [Central Research Laboratory, Sree Balaji Medical College & Hospital, Bharath University, BIHER, Chrompet, Chennai 600044, Tamil Nadu (India); UNESCO UNISA Africa Chair in Nanosciences & Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Lakshmanan, V. [Dept of Physics, A.C.T College of Engineering & Technology, Nelvoy 603107 Kancheepuram (Dt), Tamil Nadu (India); Baskaran, I. [Dept of Physics, Arignar Anna Government Arts College, Cheyyar 604407, Tamil Nadu (India); Sivakumar, K. [Dept of Physics, Anna University, Chennai 600025, Tamil Nadu (India); Ladchumananandasivam, Rasiah [Dept of Textile Engineering & Post Graduate Programme in Mechanical Engineering Centre of Technology, Federal University of Rio Grande do Norte, Natal (Brazil); Kennedy, J. [UNESCO UNISA Africa Chair in Nanosciences & Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); The MacDiarmid Institute for Advanced Materials and Nanotechnology, PO Box 600, Wellington (New Zealand); Maaza, M., E-mail: maaza@tlabs.ac.za [UNESCO UNISA Africa Chair in Nanosciences & Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa)

    2016-06-25

    Nanocrystalline TiO{sub 2} powders have been selectively prepared by the simple combustion reaction method using urea as a fuel. The crystalline powder was obtained using a silica basin heated directly on a hot plate at 500 °C until self-ignition occurred. After combustion process, the calcined products were obtained by heating the as-prepared powders for 1 h in air atmosphere at various sintering temperatures [500–900 °C]. The obtained nanopowder materials were systematically characterized by X-day diffraction (XRD), micro-Raman, UV–visible absorption (UV–vis), and Fourier transform infrared (FT-IR) spectroscopics. Powder XRD pattern shows the good agreement rutile phase structured TiO{sub 2} and the sharp diffraction peaks indicates good for crystallinity. The size of a symmetry of the nanoparticles have been measured with aid of a scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), and Brunauer, Emmett and Teller (BET) surface studies. The crystallinity of the powders was found to increase with respect to calcination temperatures. The average specific surface area of the particle was probed using gas adsorption–desorption measurements. Raman spectroscopy experiment was performed to ascertain the nature of TiO{sub 2} powder quality. UV–vis absorption spectra results showed the changes in the absorption edges of TiO{sub 2} report to increasing the calcinations temperatures. - Highlights: • TiO{sub 2} Nanocrystalline powders were prepared by simple combustion reaction method. • Calcined TiO{sub 2} nanopowder obtained by heating for 1 hr in air atmosphere at 500–900 °C. • Systematic characterization employed by XRD, micro-Raman, Optical, SEM, HRTEM. • The size symmetry of nanoparticles measured by electron microscopes BET methods. • Calcinations raises the crystallinity size enhanced for future opto-electronic devices.

  16. Mid-infrared Semiconductor Optoelectronics

    CERN Document Server

    Krier, Anthony

    2006-01-01

    The practical realisation of optoelectronic devices operating in the 2–10 µm (mid-infrared) wavelength range offers potential applications in a variety of areas from environmental gas monitoring around oil rigs and landfill sites to the detection of pharmaceuticals, particularly narcotics. In addition, an atmospheric transmission window exists between 3 µm and 5 µm that enables free-space optical communications, thermal imaging applications and the development of infrared measures for "homeland security". Consequently, the mid-infrared is very attractive for the development of sensitive optical sensor instrumentation. Unfortunately, the nature of the likely applications dictates stringent requirements in terms of laser operation, miniaturisation and cost that are difficult to meet. Many of the necessary improvements are linked to a better ability to fabricate and to understand the optoelectronic properties of suitable high-quality epitaxial materials and device structures. Substantial progress in these m...

  17. Perovskite Materials: Solar Cell and Optoelectronic Applications

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bin [ORNL; Geohegan, David B [ORNL; Xiao, Kai [ORNL

    2017-01-01

    Hybrid organometallic trihalide perovskites are promising candidates in the applications for next-generation, high-performance, low-cost optoelectronic devices, including photovoltaics, light emitting diodes, and photodetectors. Particularly, the solar cells based on this type of materials have reached 22% lab scale power conversion efficiency in only about seven years, comparable to the other thin film photovoltaic technologies. Hybrid perovskite materials not only exhibit superior optoelectronic properties, but also show many interesting physical properties such as ion migration and defect physics, which may allow the exploration of more device functionalities. In this article, the fundamental understanding of the interrelationships between crystal structure, electronic structure, and material properties is discussed. Various chemical synthesis and processing methods for superior device performance in solar cells and optoelectronic devices are reviewed.

  18. Displacement of teeth without and with bonded fixed orthodontic retainers: 3D analysis using triangular target frames and optoelectronic motion tracking device.

    Science.gov (United States)

    Chakroun, Firas; Colombo, Vera; Lie Sam Foek, Dave; Gallo, Luigi Maria; Feilzer, Albert; Özcan, Mutlu

    2018-06-06

    The objective of this study was to evaluate the anterior tooth movement without and with bonded fixed orthodontic retainers under incremental loading conditions. Six extracted mandibular anterior human teeth were embedded in acrylic resin in True Form I Arch type and 3D reconstruction of Digital Volume Tomography (DVT) images (0.4 mm 3 voxels) were obtained. The anatomy of each tooth was segmented and digitally reconstructed using 3D visualization software for medical images (AMIRA, FEI SVG). The digital models of the teeth were repositioned to form an arch with constant curvature using a CAD software (Rhinoceros) and a base holder was designed fitting the shape of the roots. The clearance between the roots and their slot in the holder was kept constant at 0.3 mm to replicate the periodontal ligament thickness. The holder and the teeth were then manufactured by 3D printing (Objet Eden 260VS, Stratasys) using a resin material for dental applications (E = 2-3 GPa). The 3D-printed teeth models were then positioned in the holder and the root compartments were filled with silicone. The procedure was repeated to obtain three identical arch models. Each model was tested for tooth mobility by applying force increasing from 5 to 30 N with 5 N increments applied perpendicular on the lingual tooth surface on the incisal one third (crosshead speed: 0.1 mm/s). The teeth on each model were first tested without retainer (control) and subsequently with the bonded retainers (braided bonded retainer wire; Multi-strand 1 × 3 high performance wire, 0.022″ × 0.016″). Tooth displacement was measured in terms of complicance (F/Δ movement) (N/mm) using custom-built optoelectronic motion tracking device (OPTIS) (accuracy: 5 µm; sampling rate: 200 Hz). The position of the object was detected through three LEDs positioned in a fixed triangular shape on a metal support (Triangular Target Frame). The measurements were repeated for three times for each tooth

  19. Nano crystals for Electronic and Optoelectronic Applications

    International Nuclear Information System (INIS)

    Zhu, T.; Cloutier, S.G.; Ivanov, I; Knappenberger Jr, K.L.; Robel, I.; Zhang, F

    2012-01-01

    Electronic and optoelectronic devices, from computers and smart cell phones to solar cells, have become a part of our life. Currently, devices with featured circuits of 45 nm in size can be fabricated for commercial use. However, further development based on traditional semiconductor is hindered by the increasing thermal issues and the manufacturing cost. During the last decade, nano crystals have been widely adopted in various electronic and optoelectronic applications. They provide alternative options in terms of ease of processing, low cost, better flexibility, and superior electronic/optoelectronic properties. By taking advantage of solution-processing, self-assembly, and surface engineering, nano crystals could serve as new building blocks for low-cost manufacturing of flexible and large area devices. Tunable electronic structures combined with small exciton binding energy, high luminescence efficiency, and low thermal conductivity make nano crystals extremely attractive for FET, memory device, solar cell, solid-state lighting/display, photodetector, and lasing applications. Efforts to harness the nano crystal quantum tunability have led to the successful demonstration of many prototype devices, raising the public awareness to the wide range of solutions that nano technology can provide for an efficient energy economy. This special issue aims to provide the readers with the latest achievements of nano crystals in electronic and optoelectronic applications, including the synthesis and engineering of nano crystals towards the applications and the corresponding device fabrication, characterization and computer modeling.

  20. Optoelectronics of Molecules and Polymers

    CERN Document Server

    Moliton, André

    2006-01-01

    Optoelectronic devices are being developed at an extraordinary rate. Organic light emitting diodes, photovoltaic devices and electro-optical modulators are pivotal to the future of displays, photosensors and solar cells, and communication technologies. This book details the theories underlying the relevant mechanisms in organic materials and covers, at a basic level, how the organic components are made. The first part of this book introduces the fundamental theories used to detail ordered solids and localised energy levels. The methods used to determine energy levels in perfectly ordered molecular and macromolecular systems are discussed, making sure that the effects of quasi-particles are not missed. The function of excitons and their transfer between two molecules are studied, and the problems associated with interfaces and charge injection into resistive media are presented. The second part details technological aspects such as the fabrication of devices based on organic materials by dry etching. The princ...

  1. FABRICATION, MORPHOLOGICAL AND OPTOELECTRONIC ...

    African Journals Online (AJOL)

    2014-12-31

    Dec 31, 2014 ... porous silicon has better optoelectronic properties than bulk .... Measurement: The morphological properties of PS layer such as nanocrystalline size, the .... excess carrier removal by internal recombination and diffusion.

  2. Synthesis of Mn{sub 0.04}Cu{sub 0.05}Zn{sub 0.91}O nanorod and its application in optoelectronic switching device

    Energy Technology Data Exchange (ETDEWEB)

    Layek, Animesh, E-mail: layekanimesh@gmail.com [Department of Physics, Bejoy Narayan Mahavidyalaya, Itachuna, Hooghly-712147 (India); Middya, Somnath [Department of Physics, Bankim Sardar College, Tangrakhali, South 24-paraganas, pin-743329 (India)

    2016-05-06

    The optical absorption of ZnO nanorod had been reduced by introducing Mn as doping element. In this present study the optical absorption of ZnO nanorod has been improved by simultaneous doping of the element Mn and Cu. The hydrothermal reaction was adopted for the synthesis. The electrical conductivity and the optical band gap of the Mn{sub 0.04}Cu{sub 0.05}Zn{sub 0.91}O were measured as 1.16 × 10{sup −3}Scm{sup −1} and 3.07eV respectively, assigned the semiconductor behavior. The light induced rectification in time dependent current response characteristic of Al/ Mn{sub 0.04}Cu{sub 0.05}Zn{sub 0.91}O/ITO was investigated to check the performance of the composite in opto-electronic switching device.

  3. Semiconductor optoelectronic infrared spectroscopy

    International Nuclear Information System (INIS)

    Hollingworth, A.R.

    2001-08-01

    We use spectroscopy to study infrared optoelectronic inter and intraband semiconductor carrier dynamics. The overall aim of this thesis was to study both III-V and Pb chalcogenide material systems in order to show their future potential use in infrared emitters. The effects of bandstructure engineering have been studied in the output characteristics of mid-IR III-V laser diodes to show which processes (defects, radiative, Auger and phonon) dominate and whether non-radiative processes can be suppressed. A new three-beam pump probe experiment was used to investigate interband recombination directly in passive materials. Experiments on PbSe and theory for non-parabolic near-mirror bands and non-degenerate statistics were in good agreement. Comparisons with HgCdTe showed a reduction in the Auger coefficient of 1-2 orders of magnitude in the PbSe. Using Landau confinement to model spatial confinement in quantum dots (QDs) 'phonon bottlenecking' was studied. The results obtained from pump probe and cyclotron resonance saturation measurements showed a clear suppression in the cooling of carriers when Landau level separation was not resonant with LO phonon energy. When a bulk laser diode was placed in a magnetic field to produce a quasi quantum wire device the resulting enhanced differential gain and reduced Auger recombination lowered I th by 30%. This result showed many peaks in the light output which occurred when the LO phonon energy was a multiple of the Landau level separation. This showed for the first time evidence of the phonon bottleneck in a working laser device. A new technique called time resolved optically detected cyclotron resonance, was used as a precursor to finding the carrier dynamics within a spatially confined quantum dot. By moving to the case of a spatial QD using an optically detected intraband resonance it was possible to measure the energy separation interband levels and conduction and valence sublevels within the dot simultaneously. Furthermore

  4. Enhanced Optoelectronic Performance of a Passivated Nanowire-Based Device: Key Information from Real-Space Imaging Using 4D Electron Microscopy

    KAUST Repository

    Khan, Jafar Iqbal; Adhikari, Aniruddha; Sun, Jingya; Priante, Davide; Bose, Riya; Shaheen, Basamat; Ng, Tien Khee; Zhao, Chao; Bakr, Osman; Ooi, Boon S.; Mohammed, Omar F.

    2016-01-01

    Managing trap states and understanding their role in ultrafast charge-carrier dynamics, particularly at surface and interfaces, remains a major bottleneck preventing further advancements and commercial exploitation of nanowire (NW)-based devices. A

  5. Perspectives in optoelectronics

    National Research Council Canada - National Science Library

    Jha, Sudhanshu S

    1995-01-01

    ..., optoelectronics is playing a major role in both applied as well as basic sciences. In years to come, i t is destined to change the face of information technology and robotics, involving optical sensing and control, information storage, signal and image processing, communications, and computing. Because of the possibility of using large bandwidths availa...

  6. Modelling of optoelectronic circuits based on resonant tunneling diodes

    Science.gov (United States)

    Rei, João. F. M.; Foot, James A.; Rodrigues, Gil C.; Figueiredo, José M. L.

    2017-08-01

    Resonant tunneling diodes (RTDs) are the fastest pure electronic semiconductor devices at room temperature. When integrated with optoelectronic devices they can give rise to new devices with novel functionalities due to their highly nonlinear properties and electrical gain, with potential applications in future ultra-wide-band communication systems (see e.g. EU H2020 iBROW Project). The recent coverage on these devices led to the need to have appropriated simulation tools. In this work, we present RTD based optoelectronic circuits simulation packages to provide circuit signal level analysis such as transient and frequency responses. We will present and discuss the models, and evaluate the simulation packages.

  7. Transparent Electrodes for Efficient Optoelectronics

    KAUST Repository

    Morales-Masis, Monica

    2017-03-30

    With the development of new generations of optoelectronic devices that combine high performance and novel functionalities (e.g., flexibility/bendability, adaptability, semi or full transparency), several classes of transparent electrodes have been developed in recent years. These range from optimized transparent conductive oxides (TCOs), which are historically the most commonly used transparent electrodes, to new electrodes made from nano- and 2D materials (e.g., metal nanowire networks and graphene), and to hybrid electrodes that integrate TCOs or dielectrics with nanowires, metal grids, or ultrathin metal films. Here, the most relevant transparent electrodes developed to date are introduced, their fundamental properties are described, and their materials are classified according to specific application requirements in high efficiency solar cells and flexible organic light-emitting diodes (OLEDs). This information serves as a guideline for selecting and developing appropriate transparent electrodes according to intended application requirements and functionality.

  8. Transparent Electrodes for Efficient Optoelectronics

    KAUST Repository

    Morales-Masis, Monica; De Wolf, Stefaan; Woods-Robinson, Rachel; Ager, Joel W.; Ballif, Christophe

    2017-01-01

    With the development of new generations of optoelectronic devices that combine high performance and novel functionalities (e.g., flexibility/bendability, adaptability, semi or full transparency), several classes of transparent electrodes have been developed in recent years. These range from optimized transparent conductive oxides (TCOs), which are historically the most commonly used transparent electrodes, to new electrodes made from nano- and 2D materials (e.g., metal nanowire networks and graphene), and to hybrid electrodes that integrate TCOs or dielectrics with nanowires, metal grids, or ultrathin metal films. Here, the most relevant transparent electrodes developed to date are introduced, their fundamental properties are described, and their materials are classified according to specific application requirements in high efficiency solar cells and flexible organic light-emitting diodes (OLEDs). This information serves as a guideline for selecting and developing appropriate transparent electrodes according to intended application requirements and functionality.

  9. Terahertz optoelectronics with surface plasmon polariton diode.

    Science.gov (United States)

    Vinnakota, Raj K; Genov, Dentcho A

    2014-05-09

    The field of plasmonics has experience a renaissance in recent years by providing a large variety of new physical effects and applications. Surface plasmon polaritons, i.e. the collective electron oscillations at the interface of a metal/semiconductor and a dielectric, may bridge the gap between electronic and photonic devices, provided a fast switching mechanism is identified. Here, we demonstrate a surface plasmon-polariton diode (SPPD) an optoelectronic switch that can operate at exceedingly large signal modulation rates. The SPPD uses heavily doped p-n junction where surface plasmon polaritons propagate at the interface between n and p-type GaAs and can be switched by an external voltage. The devices can operate at transmission modulation higher than 98% and depending on the doping and applied voltage can achieve switching rates of up to 1 THz. The proposed switch is compatible with the current semiconductor fabrication techniques and could lead to nanoscale semiconductor-based optoelectronics.

  10. Insulating materials for optoelectronics

    International Nuclear Information System (INIS)

    Agullo-Lopez, F.

    1990-01-01

    Optoelectronics is an interdisciplinary field. Basic functions of an optoelectronic system include the generator of the optical signal, its transmission and handling and, finally, its detection, storage and display. A large variety of semiconductor and insulating materials are used or are being considered to perform those functions. The authors focus on insulating materials, mostly oxides. For signal generation, tunable solid state lasers, either vibronic or those based oon colour centres are briefly described, and their main operating parameters summarized. Reference is made to some developments on fiber and waveguide lasers. Relevant physical features of the silica fibres used for low-loss, long-band, optical transmission are reviewed, as well as present efforts to further reduce attenuation in the mid-infrared range. Particular attention is paid to photorefractive materials (LiNbO 3 , BGO, BSO, etc.), which are being investigated

  11. Opto-electronic properties and light-emitting device application of widegap layered oxychalcogenides: LaCuOCh (Ch=chalcogen) and La2CdO2Se2

    International Nuclear Information System (INIS)

    Hiramatsu, Hidenori; Hirano, Masahiro; Kamioka, Hayato; Ueda, Kazushige; Ohta, Hiromichi; Kamiya, Toshio; Hosono, Hideo

    2006-01-01

    Electronic and optical properties of widegap oxychalcogenides, LaCuOCh (Ch chalcogen) and La 2 CdO 2 Se 2 , are reviewed with a focus on those relevant to their layered crystal structures, including high hole mobility, degenerate p-type conduction, room temperature exciton, and large third order optical nonlinearity. In particular, the widegap p-type metallic conduction was realized in Mg-doped LaCuOSe: the first demonstration among any class of widegap materials including GaN:Mg. Furthermore, we demonstrate the room temperature operation of a blue light-emitting diode using a pn hetero-junction composed of a LaCuOSe epilayer and an n-type amorphous InGaZn 5 O 8 . Those results strongly suggest that a series of the layered oxychalcogenides are applicable to the light-emitting layers in opto-electronic devices that operate in the ultraviolet-blue region as well as to transparent p-type conductors. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  12. Discharge amplified photo-emission from ultra-thin films applied to tuning work function of transparent electrodes in organic opto-electronic devices

    International Nuclear Information System (INIS)

    Gentle, A.R.; Smith, G.B.; Watkins, S.E.

    2013-01-01

    A novel photoemission technique utilising localised discharge amplification of photo-yield is reported. It enables fast, accurate measurement of work function and ionisation potential for ultra-thin buffer layers vacuum deposited onto single and multilayer transparent conducting electrodes for organic solar cells and OLED's. Work function in most traditional transparent electrodes has to be raised to maximise charge transfer while high transmittance and high conductance must be retained. Results are presented for a range of metal oxide buffers, which achieve this goal. This compact photo-yield spectroscopy tool with its fast turn-around has been a valuable development aid since ionisation potential can vary significantly as deposition conditions change slightly, and as ultra-thin films grow. It has also been useful in tracking the impact of different post deposition cleaning treatments along with some storage and transport protocols, which can adversely reduce ionisation potential and hence subsequent device performance.

  13. Electron microscopy study of advanced heterostructures for optoelectronics

    NARCIS (Netherlands)

    Katcki, J.; Ratajczak, J.; Phillipp, F.; Muszalski, J.; Bugajski, M.; Chen, J.X.; Fiore, A.

    2003-01-01

    The application of cross-sectional transmission electron microscopy and SEM to the investigation of optoelectronic devices are reviewed. Special attention was paid to the electron microscopy assessment of the growth perfection of such crucial elements of the devices like quantum wells, quantum dots,

  14. Graphene optoelectronics synthesis, characterization, properties, and applications

    CERN Document Server

    bin M Yusoff, Abdul Rashid

    2014-01-01

    This first book on emerging applications for this innovative material gives an up-to-date account of the many opportunities graphene offers high-end optoelectronics.The text focuses on potential as well as already realized applications, discussing metallic and passive components, such as transparent conductors and smart windows, as well as high-frequency devices, spintronics, photonics, and terahertz devices. Also included are sections on the fundamental properties, synthesis, and characterization of graphene. With its unique coverage, this book will be welcomed by materials scientists, solid-

  15. Monolithic optoelectronic integrated broadband optical receiver with graphene photodetectors

    Directory of Open Access Journals (Sweden)

    Cheng Chuantong

    2017-07-01

    Full Text Available Optical receivers with potentially high operation bandwidth and low cost have received considerable interest due to rapidly growing data traffic and potential Tb/s optical interconnect requirements. Experimental realization of 65 GHz optical signal detection and 262 GHz intrinsic operation speed reveals the significance role of graphene photodetectors (PDs in optical interconnect domains. In this work, a novel complementary metal oxide semiconductor post-backend process has been developed for integrating graphene PDs onto silicon integrated circuit chips. A prototype monolithic optoelectronic integrated optical receiver has been successfully demonstrated for the first time. Moreover, this is a firstly reported broadband optical receiver benefiting from natural broadband light absorption features of graphene material. This work is a perfect exhibition of the concept of monolithic optoelectronic integration and will pave way to monolithically integrated graphene optoelectronic devices with silicon ICs for three-dimensional optoelectronic integrated circuit chips.

  16. Monolithic optoelectronic integrated broadband optical receiver with graphene photodetectors

    Science.gov (United States)

    Cheng, Chuantong; Huang, Beiju; Mao, Xurui; Zhang, Zanyun; Zhang, Zan; Geng, Zhaoxin; Xue, Ping; Chen, Hongda

    2017-07-01

    Optical receivers with potentially high operation bandwidth and low cost have received considerable interest due to rapidly growing data traffic and potential Tb/s optical interconnect requirements. Experimental realization of 65 GHz optical signal detection and 262 GHz intrinsic operation speed reveals the significance role of graphene photodetectors (PDs) in optical interconnect domains. In this work, a novel complementary metal oxide semiconductor post-backend process has been developed for integrating graphene PDs onto silicon integrated circuit chips. A prototype monolithic optoelectronic integrated optical receiver has been successfully demonstrated for the first time. Moreover, this is a firstly reported broadband optical receiver benefiting from natural broadband light absorption features of graphene material. This work is a perfect exhibition of the concept of monolithic optoelectronic integration and will pave way to monolithically integrated graphene optoelectronic devices with silicon ICs for three-dimensional optoelectronic integrated circuit chips.

  17. Metal Complexes for Organic Optoelectronic Applications

    Science.gov (United States)

    Huang, Liang

    Organic optoelectronic devices have drawn extensive attention by over the past two decades. Two major applications for Organic optoelectronic devices are efficient organic photovoltaic devices(OPV) and organic light emitting diodes (OLED). Organic Solar cell has been proven to be compatible with the low cost, large area bulk processing technology and processed high absorption efficiencies compared to inorganic solar cells. Organic light emitting diodes are a promising approach for display and solid state lighting applications. To improve the efficiency, stability, and materials variety for organic optoelectronic devices, several emissive materials, absorber-type materials, and charge transporting materials were developed and employed in various device settings. Optical, electrical, and photophysical studies of the organic materials and their corresponding devices were thoroughly carried out. In this thesis, Chapter 1 provides an introduction to the background knowledge of OPV and OLED research fields presented. Chapter 2 discusses new porphyrin derivatives- azatetrabenzylporphyrins for OPV and near infrared OLED applications. A modified synthetic method is utilized to increase the reaction yield of the azatetrabenzylporphyrin materials and their photophysical properties, electrochemical properties are studied. OPV devices are also fabricated using Zinc azatetrabenzylporphyrin as donor materials. Pt(II) azatetrabenzylporphyrin were also synthesized and used in near infra-red OLED to achieve an emission over 800 nm with reasonable external quantum efficiencies. Chapter 3, discusses the synthesis, characterization, and device evaluation of a series of tetradentate platinum and palladium complexesfor single doped white OLED applications and RGB white OLED applications. Devices employing some of the developed emitters demonstrated impressively high external quantum efficiencies within the range of 22%-27% for various emitter concentrations. And the palladium complex, i

  18. Optoelectronic interconnects for 3D wafer stacks

    Science.gov (United States)

    Ludwig, David; Carson, John C.; Lome, Louis S.

    1996-01-01

    Wafer and chip stacking are envisioned as means of providing increased processing power within the small confines of a three-dimensional structure. Optoelectronic devices can play an important role in these dense 3-D processing electronic packages in two ways. In pure electronic processing, optoelectronics can provide a method for increasing the number of input/output communication channels within the layers of the 3-D chip stack. Non-free space communication links allow the density of highly parallel input/output ports to increase dramatically over typical edge bus connections. In hybrid processors, where electronics and optics play a role in defining the computational algorithm, free space communication links are typically utilized for, among other reasons, the increased network link complexity which can be achieved. Free space optical interconnections provide bandwidths and interconnection complexity unobtainable in pure electrical interconnections. Stacked 3-D architectures can provide the electronics real estate and structure to deal with the increased bandwidth and global information provided by free space optical communications. This paper will provide definitions and examples of 3-D stacked architectures in optoelectronics processors. The benefits and issues of these technologies will be discussed.

  19. Photonic Structure-Integrated Two-Dimensional Material Optoelectronics

    Directory of Open Access Journals (Sweden)

    Tianjiao Wang

    2016-12-01

    Full Text Available The rapid development and unique properties of two-dimensional (2D materials, such as graphene, phosphorene and transition metal dichalcogenides enable them to become intriguing candidates for future optoelectronic applications. To maximize the potential of 2D material-based optoelectronics, various photonic structures are integrated to form photonic structure/2D material hybrid systems so that the device performance can be manipulated in controllable ways. Here, we first introduce the photocurrent-generation mechanisms of 2D material-based optoelectronics and their performance. We then offer an overview and evaluation of the state-of-the-art of hybrid systems, where 2D material optoelectronics are integrated with photonic structures, especially plasmonic nanostructures, photonic waveguides and crystals. By combining with those photonic structures, the performance of 2D material optoelectronics can be further enhanced, and on the other side, a high-performance modulator can be achieved by electrostatically tuning 2D materials. Finally, 2D material-based photodetector can also become an efficient probe to learn the light-matter interactions of photonic structures. Those hybrid systems combine the advantages of 2D materials and photonic structures, providing further capacity for high-performance optoelectronics.

  20. Multifunctional optoelectronic devices based on perovskites

    KAUST Repository

    Saidaminov, Makhsud I.; Bakr, Osman

    2017-01-01

    Embodiments of the present disclosure provide methods of growing halide films (e.g., single crystal halide perovskites or multi-crystal halide perovskites) on a structure, dual-mode photodetectors, methods of use, and the like.

  1. Optoelectronic Devices Based on Novel Semiconductor Structures

    Science.gov (United States)

    2006-06-14

    J. C. Pearson, C. Kadow, A. W. Jackson, and A. C. Gossard, Appl. Phys. Lett. 74, 2872 (1999). 11. F. Zernike , Jr., and P. R. Berman, Phys. Rev. Lett...G. Sun, and R. A. Soref, Appl. Phys. Lett. 78, 401 (2001). 8. F. Jr. Zernike and P. R. Berman, Phys. Rev. Lett. 15, 999 (1965). 9. K. Kawase, T...in successive InAs layers, resulting in a substantially wide miniband [1]. Such a large width manifests the quasi- 3D properties of the SL’s. On the

  2. Multifunctional optoelectronic devices based on perovskites

    KAUST Repository

    Saidaminov, Makhsud I.

    2017-10-19

    Embodiments of the present disclosure provide methods of growing halide films (e.g., single crystal halide perovskites or multi-crystal halide perovskites) on a structure, dual-mode photodetectors, methods of use, and the like.

  3. Optoelectronic Devices Based on Novel Semiconductor Structures

    National Research Council Canada - National Science Library

    Ding, Yujie

    1997-01-01

    .... We have set up a state-of-the-art nonlinear optics lab. We have systematically investigated spatially-localized band-gap renormalization and band-filling effects, photoluminescence saturation due to interface traps, and tunneling of heavy holes...

  4. Integrated optoelectronic materials and circuits for optical interconnects

    International Nuclear Information System (INIS)

    Hutcheson, L.D.

    1988-01-01

    Conventional interconnect and switching technology is rapidly becoming a critical issue in the realization of systems using high speed silicon and GaAs based technologies. In recent years clock speeds and on-chip density for VLSI/VHSIC technology has made packaging these high speed chips extremely difficult. A strong case can be made for using optical interconnects for on-chip/on-wafer, chip-to-chip and board-to-board high speed communications. GaAs integrated optoelectronic circuits (IOC's) are being developed in a number of laboratories for performing Input/Output functions at all levels. In this paper integrated optoelectronic materials, electronics and optoelectronic devices are presented. IOC's are examined from the standpoint of what it takes to fabricate the devices and what performance can be expected

  5. Bandgap engineering by substitution of S by Se in nanostructured ZnS1-xSex thin films grown by soft chemical route for nontoxic optoelectronic device applications

    International Nuclear Information System (INIS)

    Sadekar, Harishchandra K.; Ghule, Anil Vithal; Sharma, Ramphal

    2011-01-01

    Highlights: → ZnS 1-x Se x (x = 0 to 1) thin films are successfully deposited on glass substrates by soft chemical route. → Structural, optical and electrical properties are studied. → Change in band gap, crystallite size and resistivity is noted with change in S:Se ratio. → Wide band gap material (ZnS 1-x Se x ) is useful for photosensor and solar cell applications. → It utilizes whole visible light spectrum and is a best alternative to conventionally used toxic CdS. - Abstract: Thin films of nanostructured ZnS 1-x Se x with optimized growth parameters were prepared by soft chemical route on glass substrates. Ammonia free precursors were used at 80 deg. C constant bath temperature. The ratio of sulphur to selenium was changed continuously by changing the composition x (0-1), while atomic concentration of zinc was kept constant. Structure, composition and surface morphology of as-deposited films were characterized by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX) and scanning electron microscopy (SEM), atomic force microscopy (AFM) respectively. XRD studies revealed that as-deposited films were nanostructured in nature with cubic zinc blended structure. It was further observed that the preferred orientations are along (1 1 1) plane and crystallite size decreased with increase in the value of x. SEM and AFM images revealed that films were uniform and pinhole free. The optical band gap (E g ) was calculated from the observed transmittance spectra by Urbach method. It was found that the band gap varied linearly from 3.71 to 2.70 eV, as composition x varies 0-1. The electrical properties' study revealed that the decrease in resistivity and increase in photosensitivity, as composition x varied 0-1. The observed interesting properties of ZnS 1-x Se x thin films justified their significance in optoelectronic device fabrication and applications, and as an environment friendly alternative to the commonly used toxic material such as CdS.

  6. Bandgap engineering by substitution of S by Se in nanostructured ZnS{sub 1-x}Se{sub x} thin films grown by soft chemical route for nontoxic optoelectronic device applications

    Energy Technology Data Exchange (ETDEWEB)

    Sadekar, Harishchandra K [Thin Film and Nanotechnology Laboratory, Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004, Maharashtra (India); Department of Physics, Arts, Commerce and Science College, Sonai 414105, Maharashtra (India); Ghule, Anil Vithal [Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004, Maharashtra (India); Sharma, Ramphal [Thin Film and Nanotechnology Laboratory, Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004, Maharashtra (India)

    2011-05-05

    Highlights: > ZnS{sub 1-x}Se{sub x} (x = 0 to 1) thin films are successfully deposited on glass substrates by soft chemical route. > Structural, optical and electrical properties are studied. > Change in band gap, crystallite size and resistivity is noted with change in S:Se ratio. > Wide band gap material (ZnS{sub 1-x}Se{sub x}) is useful for photosensor and solar cell applications. > It utilizes whole visible light spectrum and is a best alternative to conventionally used toxic CdS. - Abstract: Thin films of nanostructured ZnS{sub 1-x}Se{sub x} with optimized growth parameters were prepared by soft chemical route on glass substrates. Ammonia free precursors were used at 80 deg. C constant bath temperature. The ratio of sulphur to selenium was changed continuously by changing the composition x (0-1), while atomic concentration of zinc was kept constant. Structure, composition and surface morphology of as-deposited films were characterized by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX) and scanning electron microscopy (SEM), atomic force microscopy (AFM) respectively. XRD studies revealed that as-deposited films were nanostructured in nature with cubic zinc blended structure. It was further observed that the preferred orientations are along (1 1 1) plane and crystallite size decreased with increase in the value of x. SEM and AFM images revealed that films were uniform and pinhole free. The optical band gap (E{sub g}) was calculated from the observed transmittance spectra by Urbach method. It was found that the band gap varied linearly from 3.71 to 2.70 eV, as composition x varies 0-1. The electrical properties' study revealed that the decrease in resistivity and increase in photosensitivity, as composition x varied 0-1. The observed interesting properties of ZnS{sub 1-x}Se{sub x} thin films justified their significance in optoelectronic device fabrication and applications, and as an environment friendly alternative to the commonly used toxic

  7. Reconfigurable Integrated Optoelectronics

    Directory of Open Access Journals (Sweden)

    Richard Soref

    2011-01-01

    Full Text Available Integrated optics today is based upon chips of Si and InP. The future of this chip industry is probably contained in the thrust towards optoelectronic integrated circuits (OEICs and photonic integrated circuits (PICs manufactured in a high-volume foundry. We believe that reconfigurable OEICs and PICs, known as ROEICs and RPICs, constitute the ultimate embodiment of integrated photonics. This paper shows that any ROEIC-on-a-chip can be decomposed into photonic modules, some of them fixed and some of them changeable in function. Reconfiguration is provided by electrical control signals to the electro-optical building blocks. We illustrate these modules in detail and discuss 3D ROEIC chips for the highest-performance signal processing. We present examples of our module theory for RPIC optical lattice filters already constructed, and we propose new ROEICs for directed optical logic, large-scale matrix switching, and 2D beamsteering of a phased-array microwave antenna. In general, large-scale-integrated ROEICs will enable significant applications in computing, quantum computing, communications, learning, imaging, telepresence, sensing, RF/microwave photonics, information storage, cryptography, and data mining.

  8. High bandgap III-V alloys for high efficiency optoelectronics

    Energy Technology Data Exchange (ETDEWEB)

    Alberi, Kirstin; Mascarenhas, Angelo; Wanlass, Mark

    2017-01-10

    High bandgap alloys for high efficiency optoelectronics are disclosed. An exemplary optoelectronic device may include a substrate, at least one Al.sub.1-xIn.sub.xP layer, and a step-grade buffer between the substrate and at least one Al.sub.1-xIn.sub.xP layer. The buffer may begin with a layer that is substantially lattice matched to GaAs, and may then incrementally increase the lattice constant in each sequential layer until a predetermined lattice constant of Al.sub.1-xIn.sub.xP is reached.

  9. Optoelectronic inventory system for special nuclear material

    International Nuclear Information System (INIS)

    Sieradzki, F.H.

    1994-01-01

    In support of the Department of Energy's Dismantlement Program, the Optoelectronics Characterization and Sensor Development Department 2231 at Sandia National Laboratories/New Mexico has developed an in situ nonintrusive Optoelectronic Inventory System (OIS) that has the potential for application wherever periodic inventory of selected material is desired. Using a network of fiber-optic links, the OIS retrieves and stores inventory signatures from data storage devices (which are permanently attached to material storage containers) while inherently providing electromagnetic pulse immunity and electrical noise isolation. Photovoltaic cells (located within the storage facility) convert laser diode optic power from a laser driver to electrical energy. When powered and triggered, the data storage devices sequentially output their digital inventory signatures through light-emitting diode/photo diode data links for retrieval and storage in a mobile data acquisition system. An item's exact location is determined through fiber-optic network and software design. The OIS provides an on-demand method for obtaining acceptable inventory reports while eliminating the need for human presence inside the material storage facility. By using modularization and prefabricated construction with mature technologies and components, an OIS installation with virtually unlimited capacity can be tailored to the customer's requirements

  10. Progress on Crystal Growth of Two-Dimensional Semiconductors for Optoelectronic Applications

    Directory of Open Access Journals (Sweden)

    Bingqi Sun

    2018-06-01

    Full Text Available Two-dimensional (2D semiconductors are thought to belong to the most promising candidates for future nanoelectronic applications, due to their unique advantages and capability in continuing the downscaling of complementary metal–oxide–semiconductor (CMOS devices while retaining decent mobility. Recently, optoelectronic devices based on novel synthetic 2D semiconductors have been reported, exhibiting comparable performance to the traditional solid-state devices. This review briefly describes the development of the growth of 2D crystals for applications in optoelectronics, including photodetectors, light-emitting diodes (LEDs, and solar cells. Such atomically thin materials with promising optoelectronic properties are very attractive for future advanced transparent optoelectronics as well as flexible and wearable/portable electronic devices.

  11. Implantable optoelectronic probes for in vivo optogenetics

    Science.gov (United States)

    Iseri, Ege; Kuzum, Duygu

    2017-06-01

    More than a decade has passed since optics and genetics came together and lead to the emerging technologies of optogenetics. The advent of light-sensitive opsins made it possible to optically trigger the neurons into activation or inhibition by using visible light. The importance of spatiotemporally isolating a segment of a neural network and controlling nervous signaling in a precise manner has driven neuroscience researchers and engineers to invest great efforts in designing high precision in vivo implantable devices. These efforts have focused on delivery of sufficient power to deep brain regions, while monitoring neural activity with high resolution and fidelity. In this review, we report the progress made in the field of hybrid optoelectronic neural interfaces that combine optical stimulation with electrophysiological recordings. Different approaches that incorporate optical or electrical components on implantable devices are discussed in detail. Advantages of various different designs as well as practical and fundamental limitations are summarized to illuminate the future of neurotechnology development.

  12. Research on the application of optoelectronics to nuclear power plants

    International Nuclear Information System (INIS)

    Shirosaki, Hidekazu; Mitsuda, Hiromichi; Kurata, Toshikazu; Soramoto, Seiki; Maekawa, Tatsuyuki.

    1995-01-01

    Optoelectronics, which is based on technologies such as laser diodes and optical fibers, is approaching the realm of practical application in the fields of optical fiber communications and compact disks etc,. In addition, laser enrichment, a type of uranium enrichment technique used in the nuclear field, can also be regarded as a product of optoelectronics. Application of optoelectronics in a wide range of fields is likely to continue in the future, and research is being conducted on coherent optical communication, optical integrated circuits, optical computers and other subjects in hopes of attaining practical application of these technologies in the future. On the other hand, digital control equipment and other related devices have been installed and data transfer using optical fibers has been implemented on a partial basis at nuclear power plants, and optoelectronics is anticipated to be applied on an even broader scale in the future, thereby creating the potential for improving plant reliability. In this research, we conducted an investigative study of technologies relating to optoelectronics, and proposed a remote monitoring system for manually operated valves that employs optical switches. Moreover, we conducted theoretical verification tests on the proposed system and carried out a feasibility study relating to application to nuclear power plants. As a result, the proposed system was found to be effective, and confirmed to have the potential of realization as a valve switching monitoring system. (author)

  13. Optoelectronics circuits manual

    CERN Document Server

    Marston, R M

    1999-01-01

    This manual is a useful single-volume guide specifically aimed at the practical design engineer, technician, and experimenter, as well as the electronics student and amateur. It deals with the subject in an easy to read, down to earth, and non-mathematical yet comprehensive manner, explaining the basic principles and characteristics of the best known devices, and presenting the reader with many practical applications and over 200 circuits. Most of the ICs and other devices used are inexpensive and readily available types, with universally recognised type numbers.The second edition

  14. An introduction to optoelectronic sensors

    CERN Document Server

    Tajani, Antonella; Cutolo, Antonello

    2009-01-01

    This invaluable book offers a comprehensive overview of the technologies and applications of optoelectronic sensors. Based on the R&D experience of more than 70 engineers and scientists, highly representative of the Italian academic and industrial community in this area, this book provides a broad and accurate description of the state-of-the-art optoelectronic technologies for sensing. The most innovative approaches, such as the use of photonic crystals, squeezed states of light and microresonators for sensing, are considered. Application areas range from environment to medicine and healthcare

  15. Ultrafast Graphene Photonics and Optoelectronics

    Science.gov (United States)

    2017-04-14

    AFRL-AFOSR-JP-TR-2017-0032 Ultrafast Graphene Photonics and Optoelectronics Kuang-Hsiung Wu National Chiao Tung University Final Report 04/14/2017...DATES COVERED (From - To) 18 Apr 2013 to 17 Apr 2016 4. TITLE AND SUBTITLE Ultrafast Graphene Photonics and Optoelectronics 5a.  CONTRACT NUMBER 5b...Prescribed by ANSI Std. Z39.18 Final Report for AOARD Grant FA2386-13-1-4022 “Ultrafast Graphene Photonics and Optoelectronics” Date May 23th, 2016

  16. Spectroscopic Studies of Semiconductor Materials for Aggressive-scaled Micro- and Opto-electronic Devices: nc-SiO2, GeO2; ng-Si, Ge and ng-Transition metal (TM) oxides

    Science.gov (United States)

    Cheng, Cheng

    Non-crystalline thin film materials are widely used in the semiconductor industry (micro- and optoelectronics) and in green energy, e.g., photovolatic applications. This dissertation under-pins these device application with studies of their electronic structures using derivative X-ray Absorption Spectroscopy (XAS) and derivative Spectroscopic Ellipsometry (SE) for the first time to experimentally determine electronic and intrinsic defect structures. Differences between electron and hole mobilities in c- (and ng-Si) and c- (and ng- Ge), make Ge channels superior to Si channels in for aggressively scaled CMOS field effect transistors (FETs). Bonding between Si and Ge substrates and gate dielectric oxides is the focus this dissertation. The primary objective of this research is to measure and interpret by ab-initio theory the electronic and intrinsic electronic defect structures mirco-electronic thin film materials. This is accomplished for the first time by combining (i) derivative XAS TEY data obtained at the Stanford Synchrotron Radiation Light Source (SSRL) with (ii) derivative Spectroscopic Ellipsometry results obtained at the J.A. Woollam Co. laboratory. All the oxides were deposited in RPECVD system with in-line AES and RHEED. Thins films and gate stacks were annealed in RTA system in Ar to determine temperature dependent changes. 2nd derivative analysis is applied on XAS and SE spectra emphasizing the conduction band (CB) and virtual bound state (VBS) regimes. 2nd derivative SE spectra for ng-Si and ng-Ge each have 3 distinct regimes: (i) 3 excitons, (ii) 2 features in the CB edge region, and (iii) 3 additional exciton features above the IP. Excitonic spectral width provides conductivity electron masses (em0*) and hence electron mobilities. The wider the energy range, the higher the electron mobility in that CB. Spectra of high-K dielectrics have an additional energy regime between the CB edge regime, and the higher eV excitons. This regime has 4 intra-d state

  17. Electroactive and Optoelectronically Active Graphene Nanofilms

    DEFF Research Database (Denmark)

    Chi, Qijin

    As an atomic-scale-thick two-dimensional material, graphene has emerged as one of the most miracle materials and has generated intensive interest in physics, chemistry and even biology in the last decade [1, 2]. Nanoscale engineering and functionalization of graphene is a crucial step for many...... applications ranging from catalysis, electronic devices, sensors to advanced energy conversion and storage [3]. This talk highlights our recent studies on electroactive and optoelectronically active graphene ultrathin films for chemical sensors and energy technology. The presentation includes a general theme...... for functionalization of graphene nanosheets, followed by showing several case studies. Our systems cover redox-active nanoparticles, electroactive supramolecular ensembles and redox enzymes which are integrated with graphene nanosheets as building blocks for the construction of functional thin films or graphene papers....

  18. Telemedicine optoelectronic biomedical data processing system

    Science.gov (United States)

    Prosolovska, Vita V.

    2010-08-01

    The telemedicine optoelectronic biomedical data processing system is created to share medical information for the control of health rights and timely and rapid response to crisis. The system includes the main blocks: bioprocessor, analog-digital converter biomedical images, optoelectronic module for image processing, optoelectronic module for parallel recording and storage of biomedical imaging and matrix screen display of biomedical images. Rated temporal characteristics of the blocks defined by a particular triggering optoelectronic couple in analog-digital converters and time imaging for matrix screen. The element base for hardware implementation of the developed matrix screen is integrated optoelectronic couples produced by selective epitaxy.

  19. Sintering effect on the optoelectronic characteristics of HgSe nanoparticle films on plastic substrates

    International Nuclear Information System (INIS)

    Byun, Kwangsub; Cho, Kyoungah; Kim, Sangsig

    2010-01-01

    The optoelectronic characteristics of HgSe nanoparticle films spin-coated on flexible plastic substrates are investigated under the illumination of 1.3 μm wavelength light. The sintering process improves the optoelectronic characteristics of the HgSe nanoparticle films. The photocurrent of the sintered HgSe nanoparticle films under the illumination of 1.3 μm wavelength light is approximately 20 times larger in magnitude than that of the non-sintered films in air at room temperature. Moreover, the endurance of the flexible optoelectronic device investigated by the continuous substrate bending test reveals that the photocurrent efficiency changes negligibly up to 250 cycles.

  20. Functional Carbon Nanocomposite, Optoelectronic, and Catalytic Coatings

    Science.gov (United States)

    Liang, Yu Teng

    Over the past couple decades, fundamental research into carbon nanomaterials has produced a steady stream of groundbreaking physical science. Their record setting mechanical strength, chemical stability, and optoelectronic performance have fueled many optimistic claims regarding the breadth and pace of carbon nanotube and graphene integration. However, present synthetic, processing, and economic constraints have precluded these materials from many practical device applications. To overcome these limitations, novel synthetic techniques, processing methodologies, device geometries, and mechanistic insight were developed in this dissertation. The resulting advancements in material production and composite device performance have brought carbon nanomaterials ever closer to commercial implementation. For improved materials processing, vacuum co-deposition was first demonstrated as viable technique for forming carbon nanocomposite films without property distorting covalent modifications. Co-deposited nanoparticle, carbon nanotube, and graphene composite films enabled rapid device prototyping and compositional optimization. Cellulosic polymer stabilizers were then shown to be highly effective carbon nanomaterial dispersants, improving graphene production yields by two orders of magnitude in common organic solvents. By exploiting polarity interactions, iterative solvent exchange was used to further increase carbon nanomaterial dispersion concentrations by an additional order of magnitude, yielding concentrated inks. On top of their low causticity, these cellulosic nanomaterial inks have highly tunable viscosities, excellent film forming capacity, and outstanding thermal stability. These processing characteristics enable the efficient scaling of carbon nanomaterial coatings and device production using existing roll-to-roll fabrication techniques. Utilizing these process improvements, high-performance gas sensing, energy storage, transparent conductor, and photocatalytic

  1. High efficiency optoelectronic terahertz sources

    Science.gov (United States)

    Lampin, Jean-François; Peytavit, Emilien; Akalin, Tahsin; Ducournau, G.; Hindle, Francis; Mouret, Gael

    2010-08-01

    We have developed a new generation of optoelectronic large bandwidth terahertz sources based on TEM horn antennas monolithically integrated with several types of photodetectors: low-temperature grown GaAs (LTG-GaAs) planar photoconductors, vertically integrated LTG-GaAs photoconductors on silicon substrate and uni-travelling-carrier photodiodes. Results of pulsed (time-domain) and photomixing (CW, frequency domain) experiments are presented.

  2. Recent trend in graphene for optoelectronics

    International Nuclear Information System (INIS)

    Chen, Yu-Bin; Liu, John S.; Lin Pang

    2013-01-01

    This study analyzes the scientific knowledge diffusion paths of graphene for optoelectronics (GFO), where graphene offers wide applications due to its thinness, high conductivity, excellent transparency, chemical stability, robustness, and flexibility. Our investigation is based on the main path analysis which establishes the citation links among the literature data in order to trace the significant sequence of knowledge development in this emerging field. We identify the main development paths of GFO up to the year 2012, along which a series of influential papers in this field are identified. The main path graph shows that knowledge diffusion occurs in key subareas, including reduced graphene oxide, chemical vapor deposition, and exfoliation techniques, which are developed for the preparation and applications of GFO. The applications cover solar cells, laser devices, sensing devices, and LCD. In addition, the main theme of GFO research evolves in sequence from small-graphene-sample preparation, to large-scale film growth, and onto prototype device fabrication. This evolution reflects a strong industrial demand for a new transparent–conductive film technology.

  3. The Cellulose Nanofibers for Optoelectronic Conversion and Energy Storage

    Directory of Open Access Journals (Sweden)

    Yongfeng Luo

    2014-01-01

    Full Text Available Cellulose widely exists in plant tissues. Due to the large pores between the cellulose units, the regular paper is nontransparent that cannot be used in the optoelectronic devices. But some chemical and physical methods such as 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO oxidation can be used to improve the pores scale between the cellulose units to reach nanometer level. The cellulose nanofibers (CNFs have good mechanical strength, flexibility, thermostability, and low thermal expansion. The paper made of these nanofibers represent a kind of novel nanostructured material with ultrahigh transparency, ultrahigh haze, conductivity, biodegradable, reproducible, low pollution, environment friendly and so on. These advantages make the novel nanostructured paper apply in the optoelectronic device possible, such as electronics energy storage devices. This kind of paper is considered most likely to replace traditional materials like plastics and glass, which is attracting widespread attention, and the related research has also been reported. The purpose of this paper is to review CNFs which are applied in optoelectronic conversion and energy storage.

  4. Light box for investigation of characteristics of optoelectronics detectors

    Science.gov (United States)

    Szreder, Agnieszka; Mazikowski, Adam

    2017-09-01

    In this paper, a light box for investigation of characteristics of optoelectronic detectors is described. The light box consists of an illumination device, an optical power sensor and a mechanical enclosure. The illumination device is based on four types of high-power light emitting diodes (LED): white light, red, green and blue. The illumination level can be varied for each LED independently by the driver and is measured by optical power sensor. The mechanical enclosure provides stable mounting points for the illumination device, sensor and the examined detector and protects the system from external light, which would otherwise strongly influence the measurement results. Uniformity of illumination distribution provided by the light box for all colors is good, making the measurement results less dependent on the position of the examined detector. The response of optoelectronic detectors can be investigated using the developed light box for each LED separately or for any combination of up to four LED types. As the red, green and blue LEDs are rather narrow bandwidth sources, spectral response of different detectors can be examined for these wavelength ranges. The described light box can be used for different applications. Its primary use is in a student laboratory setup for investigation of characteristics of optoelectronic detectors. Moreover, it can also be used in various colorimetric or photographic applications. Finally, it will be used as a part of demonstrations from the fields of vision and color, performed during science fairs and outreach activities increasing awareness of optics and photonics.

  5. Integrated NEMS and optoelectronics for sensor applications.

    Energy Technology Data Exchange (ETDEWEB)

    Czaplewski, David A.; Serkland, Darwin Keith; Olsson, Roy H., III; Bogart, Gregory R. (Symphony Acoustics, Rio Rancho, NM); Krishnamoorthy, Uma; Warren, Mial E.; Carr, Dustin Wade (Symphony Acoustics, Rio Rancho, NM); Okandan, Murat; Peterson, Kenneth Allen

    2008-01-01

    This work utilized advanced engineering in several fields to find solutions to the challenges presented by the integration of MEMS/NEMS with optoelectronics to realize a compact sensor system, comprised of a microfabricated sensor, VCSEL, and photodiode. By utilizing microfabrication techniques in the realization of the MEMS/NEMS component, the VCSEL and the photodiode, the system would be small in size and require less power than a macro-sized component. The work focused on two technologies, accelerometers and microphones, leveraged from other LDRD programs. The first technology was the nano-g accelerometer using a nanophotonic motion detection system (67023). This accelerometer had measured sensitivity of approximately 10 nano-g. The Integrated NEMS and optoelectronics LDRD supported the nano-g accelerometer LDRD by providing advanced designs for the accelerometers, packaging, and a detection scheme to encapsulate the accelerometer, furthering the testing capabilities beyond bench-top tests. A fully packaged and tested die was never realized, but significant packaging issues were addressed and many resolved. The second technology supported by this work was the ultrasensitive directional microphone arrays for military operations in urban terrain and future combat systems (93518). This application utilized a diffraction-based sensing technique with different optical component placement and a different detection scheme from the nano-g accelerometer. The Integrated NEMS LDRD supported the microphone array LDRD by providing custom designs, VCSELs, and measurement techniques to accelerometers that were fabricated from the same operational principles as the microphones, but contain proof masses for acceleration transduction. These devices were packaged at the end of the work.

  6. Graphene and Two-Dimensional Materials for Optoelectronic Applications

    Directory of Open Access Journals (Sweden)

    Andreas Bablich

    2016-03-01

    Full Text Available This article reviews optoelectronic devices based on graphene and related two-dimensional (2D materials. The review includes basic considerations of process technology, including demonstrations of 2D heterostructure growth, and comments on the scalability and manufacturability of the growth methods. We then assess the potential of graphene-based transparent conducting electrodes. A major part of the review describes photodetectors based on lateral graphene p-n junctions and Schottky diodes. Finally, the progress in vertical devices made from 2D/3D heterojunctions, as well as all-2D heterostructures is discussed.

  7. Design of optoelectronic system for optical diffusion tomography

    Directory of Open Access Journals (Sweden)

    Erakhtin Igor

    2017-01-01

    Full Text Available This article explores issues connected with the circuit design of a device for optical diffusion tomography, which we are currently designing. We plan to use the device in experimental studies for the development of a faster method of brain hematoma detection. We reviewed currently existing methods for emergency diagnosis of hematomas, primarily the Infrascanner model 2000, for which we identified weaknesses, and outlined suggestions for improvements. This article describes the method of scanning tissues based on a triangulated arrangement of sources and receivers of optical radiation, and it discusses the optoelectronic system that implements that principle.

  8. Advances in graphene-based optoelectronics, plasmonics and photonics

    International Nuclear Information System (INIS)

    Nguyen, Bich Ha; Nguyen, Van Hieu

    2016-01-01

    Since the early works on graphene it has been remarked that graphene is a marvelous electronic material. Soon after its discovery, graphene was efficiently utilized in the fabrication of optoelectronic, plasmonic and photonic devices, including graphene-based Schottky junction solar cells. The present work is a review of the progress in the experimental research on graphene-based optoelectronics, plasmonics and photonics, with the emphasis on recent advances. The main graphene-based optoelectronic devices presented in this review are photodetectors and modulators. In the area of graphene-based plasmonics, a review of the plasmonic nanostructures enhancing or tuning graphene-light interaction, as well as of graphene plasmons is presented. In the area of graphene-based photonics, we report progress on fabrication of different types of graphene quantum dots as well as functionalized graphene and graphene oxide, the research on the photoluminescence and fluorescence of graphene nanostructures as well as on the energy exchange between graphene and semiconductor quantum dots. In particular, the promising achievements of research on graphene-based Schottky junction solar cells is presented. (review)

  9. Optoelectronic properties of four azobenzene-based iminopyridine ligands for photovoltaic application

    Directory of Open Access Journals (Sweden)

    Aziz El alamy

    2017-11-01

    Full Text Available Because of organic π-conjugated materials’ optoelectronic properties and potential applications in a wide range of electronic and optoelectronic devices, such as organic solar cells, these materials, including both polymers and oligomers, have been widely studied in recent years. This work reposts a theoretical study using the DFT method on four azobenzene-based iminopyridines. The theoretical ground-state geometry, electronic structure and optoelectronic parameters (highest occupied molecular orbital (HOMO, lowest unoccupied molecular orbital (LUMO energy levels, open-circuit voltage (Voc and oscillator strengths (O.S of the studied molecules were obtained using the density functional theory (DFT and time-dependent (TDDFT approaches. The effects of the structure length and substituents on the geometric and optoelectronic properties of these materials are discussed to investigate the relationship between the molecular structure and the optoelectronic properties. The results of this study are consistent with the experimental ones and suggest that these materials as good candidates for use in photovoltaic devices. Keywords: π-conjugated materials, azobenzene, optoelectronic properties, DFT calculations, HOMO-LUMO gap

  10. Increased Optoelectronic Quality and Uniformity of Hydrogenated p-InP Thin Films

    KAUST Repository

    Wang, Hsin-Ping; Sutter-Fella, Carolin M.; Lobaccaro, Peter; Hettick, Mark; Zheng, Maxwell; Lien, Der-Hsien; Miller, D. Westley; Warren, Charles W.; Roe, Ellis T; Lonergan, Mark C; Guthrey, Harvey L.; Haegel, Nancy M.; Ager, Joel W.; Carraro, Carlo; Maboudian, Roya; He, Jr-Hau; Javey, Ali

    2016-01-01

    The thin-film vapor-liquid-solid (TF-VLS) growth technique presents a promising route for high quality, scalable and cost-effective InP thin films for optoelectronic devices. Towards this goal, careful optimization of material properties and device performance is of utmost interest. Here, we show that exposure of polycrystalline Zn-doped TF-VLS InP to a hydrogen plasma (in the following referred to as hydrogenation) results in improved optoelectronic quality as well as lateral optoelectronic uniformity. A combination of low temperature photoluminescence and transient photocurrent spectroscopy were used to analyze the energy position and relative density of defect states before and after hydrogenation. Notably, hydrogenation reduces the intra-gap defect density by one order of magnitude. As a metric to monitor lateral optoelectronic uniformity of polycrystalline TF-VLS InP, photoluminescence and electron beam induced current mapping reveal homogenization of the grain versus grain boundary upon hydrogenation. At the device level, we measured more than 260 TF-VLS InP solar cells before and after hydrogenation to verify the improved optoelectronic properties. Hydrogenation increased the average open-circuit voltage (VOC) of individual TF-VLS InP solar cells by up to 130 mV, and reduced the variance in VOC for the analyzed devices.

  11. Increased Optoelectronic Quality and Uniformity of Hydrogenated p-InP Thin Films

    KAUST Repository

    Wang, Hsin-Ping

    2016-06-08

    The thin-film vapor-liquid-solid (TF-VLS) growth technique presents a promising route for high quality, scalable and cost-effective InP thin films for optoelectronic devices. Towards this goal, careful optimization of material properties and device performance is of utmost interest. Here, we show that exposure of polycrystalline Zn-doped TF-VLS InP to a hydrogen plasma (in the following referred to as hydrogenation) results in improved optoelectronic quality as well as lateral optoelectronic uniformity. A combination of low temperature photoluminescence and transient photocurrent spectroscopy were used to analyze the energy position and relative density of defect states before and after hydrogenation. Notably, hydrogenation reduces the intra-gap defect density by one order of magnitude. As a metric to monitor lateral optoelectronic uniformity of polycrystalline TF-VLS InP, photoluminescence and electron beam induced current mapping reveal homogenization of the grain versus grain boundary upon hydrogenation. At the device level, we measured more than 260 TF-VLS InP solar cells before and after hydrogenation to verify the improved optoelectronic properties. Hydrogenation increased the average open-circuit voltage (VOC) of individual TF-VLS InP solar cells by up to 130 mV, and reduced the variance in VOC for the analyzed devices.

  12. Optoelectronic properties of valence-state-controlled amorphous niobium oxide

    Science.gov (United States)

    Onozato, Takaki; Katase, Takayoshi; Yamamoto, Akira; Katayama, Shota; Matsushima, Koichi; Itagaki, Naho; Yoshida, Hisao; Ohta, Hiromichi

    2016-06-01

    In order to understand the optoelectronic properties of amorphous niobium oxide (a-NbO x ), we have investigated the valence states, local structures, electrical resistivity, and optical absorption of a-NbO x thin films with various oxygen contents. It was found that the valence states of Nb ion in a-NbO x films can be controlled from 5+  to 4+  by reducing oxygen pressure during film deposition at room temperature, together with changing the oxide-ion arrangement around Nb ion from Nb2O5-like to NbO2-like local structure. As a result, a four orders of magnitude reduction in the electrical resistivity of a-NbO x films was observed with decreasing oxygen content, due to the carrier generation caused by the appearance and increase of an oxygen-vacancy-related subgap state working as an electron donor. The tunable optoelectronic properties of a-NbO x films by valence-state-control with oxygen-vacancy formation will be useful for potential flexible optoelectronic device applications.

  13. Influence of Molecular Conformations and Microstructure on the Optoelectronic Properties of Conjugated Polymers

    Directory of Open Access Journals (Sweden)

    Ioan Botiz

    2014-03-01

    Full Text Available It is increasingly obvious that the molecular conformations and the long-range arrangement that conjugated polymers can adopt under various experimental conditions in bulk, solutions or thin films, significantly impact their resulting optoelectronic properties. As a consequence, the functionalities and efficiencies of resulting organic devices, such as field-effect transistors, light-emitting diodes, or photovoltaic cells, also dramatically change due to the close structure/property relationship. A range of structure/optoelectronic properties relationships have been investigated over the last few years using various experimental and theoretical methods, and, further, interesting correlations are continuously revealed by the scientific community. In this review, we discuss the latest findings related to the structure/optoelectronic properties interrelationships that exist in organic devices fabricated with conjugated polymers in terms of charge mobility, absorption, photoluminescence, as well as photovoltaic properties.

  14. Progress in complementary metal–oxide–semiconductor silicon photonics and optoelectronic integrated circuits

    International Nuclear Information System (INIS)

    Chen Hongda; Zhang Zan; Huang Beiju; Mao Luhong; Zhang Zanyun

    2015-01-01

    Silicon photonics is an emerging competitive solution for next-generation scalable data communications in different application areas as high-speed data communication is constrained by electrical interconnects. Optical interconnects based on silicon photonics can be used in intra/inter-chip interconnects, board-to-board interconnects, short-reach communications in datacenters, supercomputers and long-haul optical transmissions. In this paper, we present an overview of recent progress in silicon optoelectronic devices and optoelectronic integrated circuits (OEICs) based on a complementary metal–oxide–semiconductor-compatible process, and focus on our research contributions. The silicon optoelectronic devices and OEICs show good characteristics, which are expected to benefit several application domains, including communication, sensing, computing and nonlinear systems. (review)

  15. Influence of Molecular Conformations and Microstructure on the Optoelectronic Properties of Conjugated Polymers

    KAUST Repository

    Botiz, Ioan; Stingelin, Natalie

    2014-01-01

    It is increasingly obvious that the molecular conformations and the long-range arrangement that conjugated polymers can adopt under various experimental conditions in bulk, solutions or thin films, significantly impact their resulting optoelectronic properties. As a consequence, the functionalities and efficiencies of resulting organic devices, such as field-effect transistors, light-emitting diodes, or photovoltaic cells, also dramatically change due to the close structure/property relationship. A range of structure/optoelectronic properties relationships have been investigated over the last few years using various experimental and theoretical methods, and, further, interesting correlations are continuously revealed by the scientific community. In this review, we discuss the latest findings related to the structure/optoelectronic properties interrelationships that exist in organic devices fabricated with conjugated polymers in terms of charge mobility, absorption, photoluminescence, as well as photovoltaic properties. © 2014 by the authors.

  16. Influence of Molecular Conformations and Microstructure on the Optoelectronic Properties of Conjugated Polymers

    KAUST Repository

    Botiz, Ioan

    2014-03-19

    It is increasingly obvious that the molecular conformations and the long-range arrangement that conjugated polymers can adopt under various experimental conditions in bulk, solutions or thin films, significantly impact their resulting optoelectronic properties. As a consequence, the functionalities and efficiencies of resulting organic devices, such as field-effect transistors, light-emitting diodes, or photovoltaic cells, also dramatically change due to the close structure/property relationship. A range of structure/optoelectronic properties relationships have been investigated over the last few years using various experimental and theoretical methods, and, further, interesting correlations are continuously revealed by the scientific community. In this review, we discuss the latest findings related to the structure/optoelectronic properties interrelationships that exist in organic devices fabricated with conjugated polymers in terms of charge mobility, absorption, photoluminescence, as well as photovoltaic properties. © 2014 by the authors.

  17. Heterostructures and quantum devices

    CERN Document Server

    Einspruch, Norman G

    1994-01-01

    Heterostructure and quantum-mechanical devices promise significant improvement in the performance of electronic and optoelectronic integrated circuits (ICs). Though these devices are the subject of a vigorous research effort, the current literature is often either highly technical or narrowly focused. This book presents heterostructure and quantum devices to the nonspecialist, especially electrical engineers working with high-performance semiconductor devices. It focuses on a broad base of technical applications using semiconductor physics theory to develop the next generation of electrical en

  18. Investigation, study and practice of optoelectronic MOOCs

    Science.gov (United States)

    Shi, Jianhua; Liu, Wei; Lei, Bing; Yao, Tianfu; Fu, Sihua

    2017-08-01

    MOOC(Massive Open Online Course) is a new teaching model that has been springing up since 2012. The typical characters are short teaching video, massive learners, flexible place and time to study, etc. Although MOOC is very popular now, opto-electronic MOOCs are not much enough to meet the need of online learners. In this paper, the phylogeny, the current situation and the characters of MOOC were described, the most famous MOOCs' websites, such as Udacity, Coursera, edX, Chinese College MOOC, xuetangx, were introduced, the opto-electronic MOOCs come from these famous MOOCs' website were investigated extensively and studied deeply, the "Application of Opto-electronic Technology MOOC" which was established by our group is introduced, and some conclusions are obtained. These conclusions can give some suggestions to the online learners who are interested in opto-electronic and the teachers who are teaching the opto-electronic curriculums. The preparation of "Opto-electronic Technology MOOC" is described in short.

  19. Enhancing electronic and optoelectronic performances of tungsten diselenide by plasma treatment.

    Science.gov (United States)

    Xie, Yuan; Wu, Enxiu; Hu, Ruixue; Qian, Shuangbei; Feng, Zhihong; Chen, Xuejiao; Zhang, Hao; Xu, Linyan; Hu, Xiaodong; Liu, Jing; Zhang, Daihua

    2018-06-21

    Transition metal dichalcogenides (TMDCs) have recently become spotlighted as nanomaterials for future electronic and optoelectronic devices. In this work, we develop an effective approach to enhance the electronic and optoelectronic performances of WSe2-based devices by N2O plasma treatment. The hole mobility and sheet density increase by 2 and 5 orders of magnitude, reaching 110 cm2 V-1 s-1 and 2.2 × 1012 cm-2, respectively, after the treatment. At the same time, the contact resistance (Rc) between WSe2 and its metal electrode drop by 5 orders of magnitude from 1.0 GΩ μm to 28.4 kΩ μm. The WSe2 photoconductor exhibits superior performance with high responsivity (1.5 × 105 A W-1), short response time (106). We have also built a lateral p-n junction on a single piece of WSe2 flake by selective plasma exposure. The junction reaches an exceedingly high rectifying ratio of 106, an excellent photoresponsivity of 2.49 A W-1 and a fast response of 8 ms. The enhanced optoelectronic performance is attributed to band-engineering through the N2O plasma treatment, which can potentially serve as an effective and versatile approach for device engineering and optimization in a wide range of electronic and optoelectronic devices based on 2D materials.

  20. Optical technology for microwave applications VI and optoelectronic signal processing for phased-array antennas III; Proceedings of the Meeting, Orlando, FL, Apr. 20-23, 1992

    Science.gov (United States)

    Yao, Shi-Kay; Hendrickson, Brian M.

    The following topics related to optical technology for microwave applications are discussed: advanced acoustooptic devices, signal processing device technologies, optical signal processor technologies, microwave and optomicrowave devices, advanced lasers and sources, wideband electrooptic modulators, and wideband optical communications. The topics considered in the discussion of optoelectronic signal processing for phased-array antennas include devices, signal processing, and antenna systems.

  1. Toward high-resolution optoelectronic retinal prosthesis

    Science.gov (United States)

    Palanker, Daniel; Huie, Philip; Vankov, Alexander; Asher, Alon; Baccus, Steven

    2005-04-01

    It has been already demonstrated that electrical stimulation of retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. Current retinal implants provide very low resolution (just a few electrodes), while several thousand pixels are required for functional restoration of sight. We present a design of the optoelectronic retinal prosthetic system that can activate a retinal stimulating array with pixel density up to 2,500 pix/mm2 (geometrically corresponding to a visual acuity of 20/80), and allows for natural eye scanning rather than scanning with a head-mounted camera. The system operates similarly to "virtual reality" imaging devices used in military and medical applications. An image from a video camera is projected by a goggle-mounted infrared LED-LCD display onto the retina, activating an array of powered photodiodes in the retinal implant. Such a system provides a broad field of vision by allowing for natural eye scanning. The goggles are transparent to visible light, thus allowing for simultaneous utilization of remaining natural vision along with prosthetic stimulation. Optical control of the implant allows for simple adjustment of image processing algorithms and for learning. A major prerequisite for high resolution stimulation is the proximity of neural cells to the stimulation sites. This can be achieved with sub-retinal implants constructed in a manner that directs migration of retinal cells to target areas. Two basic implant geometries are described: perforated membranes and protruding electrode arrays. Possibility of the tactile neural stimulation is also examined.

  2. Laser applications in the electronics and optoelectronics industry in Japan

    Science.gov (United States)

    Washio, Kunihiko

    1999-07-01

    This paper explains current status and technological trends in laser materials processing applications in electronics and optoelectronics industry in Japan. Various laser equipment based on solid state lasers or gas lasers such as excimer lasers or CO2 lasers has been developed and applied in manufacturing electronic and optoelectronic devices to meet the strong demands for advanced device manufacturing technologies for high-performance, lightweight, low power-consumption portable digital electronic appliances, cellular mobile phones, personal computers, etc. Representative applications of solid-state lasers are, opaque and clear defects repairing of photomasks for LSIs and LCDs, trimming of thick-film chip resistors and low resistance metal resistors, laser cutting and drilling of thin films for high-pin count semiconductor CSP packages, laser patterning of thin-film amorphous silicon solar cells, and laser welding of electronic components such as hard-disk head suspensions, optical modules, miniature relays and lithium ion batteries. Compact and highly efficient diode- pumped and Q-switched solid-state lasers in second or third harmonic operation mode are now being increasingly incorporated in various laser equipment for fine material processing. Representative applications of excimer lasers are, sub-quarter micron design-rule LSI lithography and low- temperature annealing of poly-silicon TFT LCD.

  3. Ultrafast Phase Comparator for Phase-Locked Loop-Based Optoelectronic Clock Recovery Systems

    DEFF Research Database (Denmark)

    Gomez-Agis, F.; Oxenløwe, Leif Katsuo; Kurimura, S.

    2009-01-01

    The authors report on a novel application of a chi((2)) nonlinear optical device as an ultrafast phase comparator, an essential element that allows an optoelectronic phase-locked loop to perform clock recovery of ultrahigh-speed optical time-division multiplexed (OTDM) signals. Particular interest...... is devoted to a quasi-phase-matching adhered-ridge-waveguide periodically poled lithium niobate (PPLN) device, which shows a sufficient high temporal resolution to resolve a 640 Gbits OTDM signal....

  4. Digital optical computers at the optoelectronic computing systems center

    Science.gov (United States)

    Jordan, Harry F.

    1991-01-01

    The Digital Optical Computing Program within the National Science Foundation Engineering Research Center for Opto-electronic Computing Systems has as its specific goal research on optical computing architectures suitable for use at the highest possible speeds. The program can be targeted toward exploiting the time domain because other programs in the Center are pursuing research on parallel optical systems, exploiting optical interconnection and optical devices and materials. Using a general purpose computing architecture as the focus, we are developing design techniques, tools and architecture for operation at the speed of light limit. Experimental work is being done with the somewhat low speed components currently available but with architectures which will scale up in speed as faster devices are developed. The design algorithms and tools developed for a general purpose, stored program computer are being applied to other systems such as optimally controlled optical communication networks.

  5. Optoelectronic analogue signal transfer for LHC detectors, 1991

    CERN Document Server

    Dowell, John D; Homer, R J; Jovanovic, P; Kenyon, I; Staley, R; Webster, K; Da Via, C; Feyt, J; Nappey, P; Stefanini, G; Dwir, B; Reinhart, F K; Davies, J; Green, N; Stewart, W; Young, T; Hall, G; Akesson, T; Jarlskog, G; Kröll, S; Nickerson, R; Jaroslawski, S; CERN. Geneva. Detector Research and Development Committee

    1991-01-01

    We propose to study and develop opto-electronic analogue front-ends based on electro-optic intensity modulators. These devices translate the detector electrical analogue signals into optical signals which are then transferred via optical fibres to photodetector receivers at the remote readout. In comparison with conventional solutions based on copper cables, this technique offers the advantages of high speed, very low power dissipation and transmission losses, compactness and immunity to electromagnetic interference. The linearity and dynamic range that can be obtained are more than adequate for central tracking detectors, and the proposed devices have considerable radiation- hardness capabilities. The large bandwidth and short transit times offer possibilities for improved triggering schemes. The proposed R&D programme is aimed at producing multi-channel "demonstrator" units for evaluation both in laboratory and beam tests. This will allow the choice of the most effective technology. A detailed study wil...

  6. Tuning the optoelectronic properties of amorphous MoOx films by reactive sputtering

    DEFF Research Database (Denmark)

    Fernandes Cauduro, André Luis; Fabrim, Zacarias Eduardo; Ahmadpour, Mehrad

    2015-01-01

    In this letter, we report on the effect of oxygen partial pressure and sputtering power on amorphous DC-sputtered MoOx films. We observe abrupt changes in the optoelectronic properties of the reported films by increasing the oxygen partial pressure from 1.00 ? 10?3 mbar to 1.37 ? 10?3 mbar during...... significantly the microstructure of the studied films. The presence of states within the band gap due to the lack of oxygen is the most probable mechanism for generat- ing a change in electrical conductivity as well as optical absorption in DC-sputtered MoOx. The large tuning range of the optoelectronic...... properties in these films holds strong promise for their implementation in optoelectronic devices....

  7. Pseudo-direct bandgap transitions in silicon nanocrystals: effects on optoelectronics and thermoelectrics

    Science.gov (United States)

    Singh, Vivek; Yu, Yixuan; Sun, Qi-C.; Korgel, Brian; Nagpal, Prashant

    2014-11-01

    While silicon nanostructures are extensively used in electronics, the indirect bandgap of silicon poses challenges for optoelectronic applications like photovoltaics and light emitting diodes (LEDs). Here, we show that size-dependent pseudo-direct bandgap transitions in silicon nanocrystals dominate the interactions between (photoexcited) charge carriers and phonons, and hence the optoelectronic properties of silicon nanocrystals. Direct measurements of the electronic density of states (DOS) for different sized silicon nanocrystals reveal that these pseudo-direct transitions, likely arising from the nanocrystal surface, can couple with the quantum-confined silicon states. Moreover, we demonstrate that since these transitions determine the interactions of charge carriers with phonons, they change the light emission, absorption, charge carrier diffusion and phonon drag (Seebeck coefficient) in nanoscaled silicon semiconductors. Therefore, these results can have important implications for the design of optoelectronics and thermoelectric devices based on nanostructured silicon.While silicon nanostructures are extensively used in electronics, the indirect bandgap of silicon poses challenges for optoelectronic applications like photovoltaics and light emitting diodes (LEDs). Here, we show that size-dependent pseudo-direct bandgap transitions in silicon nanocrystals dominate the interactions between (photoexcited) charge carriers and phonons, and hence the optoelectronic properties of silicon nanocrystals. Direct measurements of the electronic density of states (DOS) for different sized silicon nanocrystals reveal that these pseudo-direct transitions, likely arising from the nanocrystal surface, can couple with the quantum-confined silicon states. Moreover, we demonstrate that since these transitions determine the interactions of charge carriers with phonons, they change the light emission, absorption, charge carrier diffusion and phonon drag (Seebeck coefficient) in

  8. Optoelectronic lessons as an interdisciplinary lecture

    Science.gov (United States)

    Wu, Dan; Wu, Maocheng; Gu, Jihua

    2017-08-01

    It is noticed that more and more students in college are passionately curious about the optoelectronic technology, since optoelectronic technology has advanced extremely quickly during the last five years and its applications could be found in a lot of domains. The students who are interested in this area may have different educational backgrounds and their majors cover science, engineering, literature and social science, etc. Our course "History of the Optoelectronic Technology" is set up as an interdisciplinary lecture of the "liberal education" at our university, and is available for all students with different academic backgrounds from any departments of our university. The main purpose of the course is to show the interesting and colorful historical aspects of the development of this technology, so that the students from different departments could absorb the academic nourishment they wanted. There are little complex derivations of physical formulas through the whole lecture, but there are still some difficulties about the lecture which is discussed in this paper.

  9. Dual-scale topology optoelectronic processor.

    Science.gov (United States)

    Marsden, G C; Krishnamoorthy, A V; Esener, S C; Lee, S H

    1991-12-15

    The dual-scale topology optoelectronic processor (D-STOP) is a parallel optoelectronic architecture for matrix algebraic processing. The architecture can be used for matrix-vector multiplication and two types of vector outer product. The computations are performed electronically, which allows multiplication and summation concepts in linear algebra to be generalized to various nonlinear or symbolic operations. This generalization permits the application of D-STOP to many computational problems. The architecture uses a minimum number of optical transmitters, which thereby reduces fabrication requirements while maintaining area-efficient electronics. The necessary optical interconnections are space invariant, minimizing space-bandwidth requirements.

  10. Optoelectronics Interfaces for Power Converters

    Directory of Open Access Journals (Sweden)

    Ovidiu Neamtu

    2009-05-01

    Full Text Available The most important issue interface is galvanicseparation between the signal part and the power board.Standards in the field have increased continuouslyelectro-security requirements on the rigidity of thedielectric and insulation resistance. Recommendations forclassical solutions require the use of galvanic separationoptoelectronics devices. Interfacing with a PC or DSP -controller is a target of interposition optical signals viathe power hardware commands.

  11. Microfluidic optoelectronic sensor for salivary diagnostics of stomach cancer.

    Science.gov (United States)

    Zilberman, Yael; Sonkusale, Sameer R

    2015-05-15

    We present a microfluidic optoelectronic sensor for saliva diagnostics with a potential application for non-invasive early diagnosis of stomach cancer. Stomach cancer is the second most common cause of cancer-related deaths in the world. The primary identified cause is infection by a gram-negative bacterium Helicobacter pylori. These bacteria secrete the enzyme urease that converts urea into carbon dioxide (CO2) and ammonia (NH3), leading to their elevated levels in breath and body fluids. The proposed optoelectronic sensor will detect clinically relevant levels of CO2 and NH3 in saliva that can potentially be used for early diagnosis of stomach cancer. The sensor is composed of the embedded in a microfluidic device array of microwells filled with ion-exchange polymer microbeads doped with various organic dyes. The optical response of this unique highly diverse sensor is monitored over a broad spectrum, which provides a platform for cross-reactive sensitivity and allows detection of CO2 and NH3 in saliva at ppm levels. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Optoelectronic line transmission an introduction to fibre optics

    CERN Document Server

    Tricker, Raymond L

    2013-01-01

    Optoelectronic Line Transmission: An Introduction to Fibre Optics presents a basic introduction as well as a background reference manual on fiber optic transmission. The book discusses the basic principles of optical line transmission; the advantages and disadvantages of optical fibers and optoelectronic signalling; the practical applications of optoelectronics; and the future of optoelectronics. The text also describes the theories of optical line transmission; fibers and cables for optical transmission; transmitters including light-emitting diodes and lasers; and receivers including photodi

  13. Optoelectronics technologies for Virtual Reality systems

    Science.gov (United States)

    Piszczek, Marek; Maciejewski, Marcin; Pomianek, Mateusz; Szustakowski, Mieczysław

    2017-08-01

    Solutions in the field of virtual reality are very strongly associated with optoelectronic technologies. This applies to both process design and operation of VR applications. Technologies such as 360 cameras and 3D scanners significantly improve the design work. What is more, HMD displays with high field of view or optoelectronic Motion Capture systems and 3D cameras guarantee an extraordinary experience in immersive VR applications. This article reviews selected technologies from the perspective of their use in a broadly defined process of creating and implementing solutions for virtual reality. There is also the ability to create, modify and adapt new approaches that show team own work (SteamVR tracker). Most of the introduced examples are effectively used by authors to create different VR applications. The use of optoelectronic technology in virtual reality is presented in terms of design and operation of the system as well as referring to specific applications. Designers and users of VR systems should take a close look on new optoelectronics solutions, as they can significantly contribute to increased work efficiency and offer completely new opportunities for virtual world reception.

  14. GaAs optoelectronic neuron arrays

    Science.gov (United States)

    Lin, Steven; Grot, Annette; Luo, Jiafu; Psaltis, Demetri

    1993-01-01

    A simple optoelectronic circuit integrated monolithically in GaAs to implement sigmoidal neuron responses is presented. The circuit integrates a light-emitting diode with one or two transistors and one or two photodetectors. The design considerations for building arrays with densities of up to 10,000/sq cm are discussed.

  15. Monocrystalline halide perovskite nanostructures for optoelectronic applications

    NARCIS (Netherlands)

    Khoram, P.

    2018-01-01

    Halide perovskites are a promising class of materials for incorporation in optoelectronics with higher efficiency and lower cost. The solution processability of these materials provides unique opportunities for simple nanostructure fabrication. In the first half of the thesis (chapter 2 and 3) we

  16. Mid-Infrared Optoelectronics: Materials and Devices. MIOMD-XII

    Science.gov (United States)

    2014-10-01

    University, 6100 Main Street, Houston, TX 77005‐1827, USA 3Dipartimento Interateneo di Fisica , Università e Politecnico di Bari Via Amendola 173, I‐70126, Bari...Lancaster University, Lancaster, LA1 4YB, UK 2School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK 3Dipartimento di Fisica

  17. Optoelectronic Device Integration in Silicon (OpSIS)

    Science.gov (United States)

    2015-10-26

    silicon-on-insulator," Opt. Express 22, 17872-17879 (2014) Y. Yang, C. Galland, Y. Liu, K. Tan , R. Ding, Q. Li, K. Bergman, T. Baehr-Jones, M...Jaeger, Nicolas AF; Chrostowski, Lukas; “Electrically tunable resonant filters in phase-shifted contra- directional couplers” IEEE Group IV Photonics... Nicolas AF; Chrostowski, Lukas; “Silicon photonic grating-assisted, contra-directional couplers” Optics express Vol. 21, No. 3; 3633-3650 (2013

  18. Piezoelectric Resonance Enhanced Microwave And Optoelectronic Interactive Devices

    Science.gov (United States)

    2013-05-01

    transimpedance amplifier ), and the voltage huu. huu is obtained by rotating the quarter wave plate and monitoring the voltage at the photodiode. As the...200 MHz was tested with a Model SR844 (Stanford Research). The high frequency limiting factor of this measurement is the transimpedance amplifier ...Voltage source Transimpedance amplifier Sync 30 4mm �� �� 000 000 0 I0 I00 000 � ��� 32 �� �� − 0 000 000 H00 0− H

  19. From mud cracks to Optoelectronic devices- Our efforts in translating ...

    Indian Academy of Sciences (India)

    Prof.GU.Kulkarni

    ….a material that is transparent to visible light and yet electrically conducting. Not a trivial solution… ... ➢Poor mechanical properties (cracks when bent) – not good for flexible electronics. ITO: Limitations ..... Crack modeling. Prof. S. Tarafadar ...

  20. Spectroscopic analysis of optoelectronic semiconductors

    CERN Document Server

    Jimenez, Juan

    2016-01-01

    This book deals with standard spectroscopic techniques which can be used to analyze semiconductor samples or devices, in both, bulk, micrometer and submicrometer scale. The book aims helping experimental physicists and engineers to choose the right analytical spectroscopic technique in order to get specific information about their specific demands. For this purpose, the techniques including technical details such as apparatus and probed sample region are described. More important, also the expected outcome from experiments is provided. This involves also the link to theory, that is not subject of this book, and the link to current experimental results in the literature which are presented in a review-like style. Many special spectroscopic techniques are introduced and their relationship to the standard techniques is revealed. Thus the book works also as a type of guide or reference book for people researching in optical spectroscopy of semiconductors.

  1. Nanomaterials for Electronics and Optoelectronics

    Science.gov (United States)

    Koehne, Jessica E.; Meyyappan, M.

    2011-01-01

    Nanomaterials such as carbon nanotubes(CNTs), graphene, and inorganic nanowires(INWs) have shown interesting electronic, mechanical, optical, thermal, and other properties and therefore have been pursued for a variety of applications by the nanotechnology community ranging from electronics to nanocomposites. While the first two are carbon-based materials, the INWs in the literature include silicon, germanium, III-V, II-VI, a variety of oxides, nitrides, antimonides and others. In this talk, first an overview of growth of these three classes of materials by CVD and PECVD will be presented along with results from characterization. Then applications in development of chemical sensors, biosensors, energy storage devices and novel memory architectures will be discussed.

  2. Fluorene-based macromolecular nanostructures and nanomaterials for organic (opto)electronics.

    Science.gov (United States)

    Xie, Ling-Hai; Yang, Su-Hui; Lin, Jin-Yi; Yi, Ming-Dong; Huang, Wei

    2013-10-13

    Nanotechnology not only opens up the realm of nanoelectronics and nanophotonics, but also upgrades organic thin-film electronics and optoelectronics. In this review, we introduce polymer semiconductors and plastic electronics briefly, followed by various top-down and bottom-up nano approaches to organic electronics. Subsequently, we highlight the progress in polyfluorene-based nanoparticles and nanowires (nanofibres), their tunable optoelectronic properties as well as their applications in polymer light-emitting devices, solar cells, field-effect transistors, photodetectors, lasers, optical waveguides and others. Finally, an outlook is given with regard to four-element complex devices via organic nanotechnology and molecular manufacturing that will spread to areas such as organic mechatronics in the framework of robotic-directed science and technology.

  3. Facile fabrication of boron nitride nanosheets-amorphous carbon hybrid film for optoelectronic applications

    KAUST Repository

    Wan, Shanhong

    2015-01-01

    A novel boron nitride nanosheets (BNNSs)-amorphous carbon (a-C) hybrid film has been deposited successfully on silicon substrates by simultaneous electrochemical deposition, and showed a good integrity of this B-C-N composite film by the interfacial bonding. This synthesis can potentially provide the facile control of the B-C-N composite film for the potential optoelectronic devices. This journal is

  4. Parallel optoelectronic trinary signed-digit division

    Science.gov (United States)

    Alam, Mohammad S.

    1999-03-01

    The trinary signed-digit (TSD) number system has been found to be very useful for parallel addition and subtraction of any arbitrary length operands in constant time. Using the TSD addition and multiplication modules as the basic building blocks, we develop an efficient algorithm for performing parallel TSD division in constant time. The proposed division technique uses one TSD subtraction and two TSD multiplication steps. An optoelectronic correlator based architecture is suggested for implementation of the proposed TSD division algorithm, which fully exploits the parallelism and high processing speed of optics. An efficient spatial encoding scheme is used to ensure better utilization of space bandwidth product of the spatial light modulators used in the optoelectronic implementation.

  5. Exceptional Optoelectronic Properties of Hydrogenated Bilayer Silicene

    Directory of Open Access Journals (Sweden)

    Bing Huang

    2014-05-01

    Full Text Available Silicon is arguably the best electronic material, but it is not a good optoelectronic material. By employing first-principles calculations and the cluster-expansion approach, we discover that hydrogenated bilayer silicene (BS shows promising potential as a new kind of optoelectronic material. Most significantly, hydrogenation converts the intrinsic BS, a strongly indirect semiconductor, into a direct-gap semiconductor with a widely tunable band gap. At low hydrogen concentrations, four ground states of single- and double-sided hydrogenated BS are characterized by dipole-allowed direct (or quasidirect band gaps in the desirable range from 1 to 1.5 eV, suitable for solar applications. At high hydrogen concentrations, three well-ordered double-sided hydrogenated BS structures exhibit direct (or quasidirect band gaps in the color range of red, green, and blue, affording white light-emitting diodes. Our findings open opportunities to search for new silicon-based light-absorption and light-emitting materials for earth-abundant, high-efficiency, optoelectronic applications.

  6. Transferable, conductive TiO{sub 2} nanotube membranes for optoelectronics

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guohua [School of Energy and Environment, Anhui University of Technology, Maanshan 243002 (China); Department of Micro and Nano Systems Technology, Vestfold University College, Horten 3184 (Norway); Chen, Ting [School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Sun, Yunlan; Chen, Guang [School of Energy and Environment, Anhui University of Technology, Maanshan 243002 (China); Wang, Kaiying, E-mail: Kaiying.Wang@hbv.no [Department of Micro and Nano Systems Technology, Vestfold University College, Horten 3184 (Norway)

    2014-08-30

    Graphical abstract: An optoelectronic device with vertical architecture offers straight conducting filaments for electron transportation. - Highlights: • Highly porous TiO{sub 2} nanotube membranes are prepared by two-step anodization. • An optoelectronic device is integrated with photocurrent transportation along the nanotube axial. • Straight conducting nano-filaments are beneficial for electron transportation. • Photoconductive performances are demonstrated under front/back-illumination. - Abstract: We report a facile approach for preparing free-standing and crystalline TiO{sub 2} nanotube membranes (TNMs) by taking advantage of differential mechanical stress between two anodic layers. The membrane exhibits visible light transmittance (∼40%) and UV absorption (∼99%) with good flexibility, which is favorable to integrate with substrates in optoelectronics. A sandwich-type device is assembled through stacking the membrane and substrates. The dependence of current-perpendicular-to-membrane vs applied voltage shows a remarkable photoconductive performance for both front and back illumination. The photocurrent value increases ∼2 or 3 orders magnitude under UV light radiation as compared to that in darkness. The photoresponse is arisen from high internal gain caused by hole trapping along the nanotube walls. This work is crucial for understanding intrinsic optical properties of nanostructured membranes.

  7. Solution growth of single crystal methylammonium lead halide perovskite nanostructures for optoelectronic and photovoltaic applications.

    Science.gov (United States)

    Fu, Yongping; Meng, Fei; Rowley, Matthew B; Thompson, Blaise J; Shearer, Melinda J; Ma, Dewei; Hamers, Robert J; Wright, John C; Jin, Song

    2015-05-06

    Understanding crystal growth and improving material quality is important for improving semiconductors for electronic, optoelectronic, and photovoltaic applications. Amidst the surging interest in solar cells based on hybrid organic-inorganic lead halide perovskites and the exciting progress in device performance, improved understanding and better control of the crystal growth of these perovskites could further boost their optoelectronic and photovoltaic performance. Here, we report new insights on the crystal growth of the perovskite materials, especially crystalline nanostructures. Specifically, single crystal nanowires, nanorods, and nanoplates of methylammonium lead halide perovskites (CH3NH3PbI3 and CH3NH3PbBr3) are successfully grown via a dissolution-recrystallization pathway in a solution synthesis from lead iodide (or lead acetate) films coated on substrates. These single crystal nanostructures display strong room-temperature photoluminescence and long carrier lifetime. We also report that a solid-liquid interfacial conversion reaction can create a highly crystalline, nanostructured MAPbI3 film with micrometer grain size and high surface coverage that enables photovoltaic devices with a power conversion efficiency of 10.6%. These results suggest that single-crystal perovskite nanostructures provide improved photophysical properties that are important for fundamental studies and future applications in nanoscale optoelectronic and photonic devices.

  8. Electrical and optoelectronic properties of gallium nitride

    International Nuclear Information System (INIS)

    Flannery, Lorraine Barbara

    2002-01-01

    substrates using the CARS25 RF source. The chemical concentration of Mg, [Mg] and the hole density, p H were found to increase both with layer thickness and Mg cell temperature in material grown at 700 deg C. A maximum free hole density, p H and mobility, μ H of 4.8 x 10 17 cm -3 and 10.7 cm 2 V -1 s -1 respectively were obtained for a 2.1 μm layer grown at a Mg cell temperature of 507 deg C. Photoconductive UV detectors were successfully fabricated from the highest quality n and p-type GaN layers grown by MBE on sapphire substrates. The p-type UV devices represented the first Mg doped p-type GaN based UV photoconductive detectors grown on sapphire substrates produced by the MBE growth method. The performances of both the n and p-type detectors were assessed by measurement of their optoelectronic and electrical properties and some conclusions were drawn regarding their operating principles. (author)

  9. Delay dynamics of neuromorphic optoelectronic nanoscale resonators: Perspectives and applications

    Science.gov (United States)

    Romeira, Bruno; Figueiredo, José M. L.; Javaloyes, Julien

    2017-11-01

    With the recent exponential growth of applications using artificial intelligence (AI), the development of efficient and ultrafast brain-like (neuromorphic) systems is crucial for future information and communication technologies. While the implementation of AI systems using computer algorithms of neural networks is emerging rapidly, scientists are just taking the very first steps in the development of the hardware elements of an artificial brain, specifically neuromorphic microchips. In this review article, we present the current state of the art of neuromorphic photonic circuits based on solid-state optoelectronic oscillators formed by nanoscale double barrier quantum well resonant tunneling diodes. We address, both experimentally and theoretically, the key dynamic properties of recently developed artificial solid-state neuron microchips with delayed perturbations and describe their role in the study of neural activity and regenerative memory. This review covers our recent research work on excitable and delay dynamic characteristics of both single and autaptic (delayed) artificial neurons including all-or-none response, spike-based data encoding, storage, signal regeneration and signal healing. Furthermore, the neural responses of these neuromorphic microchips display all the signatures of extended spatio-temporal localized structures (LSs) of light, which are reviewed here in detail. By taking advantage of the dissipative nature of LSs, we demonstrate potential applications in optical data reconfiguration and clock and timing at high-speeds and with short transients. The results reviewed in this article are a key enabler for the development of high-performance optoelectronic devices in future high-speed brain-inspired optical memories and neuromorphic computing.

  10. The Electrical and Optical Properties of Organometal Halide Perovskites Relevant to Optoelectronic Performance

    KAUST Repository

    Adinolfi, Valerio

    2017-10-12

    Organometal halide perovskites are under intense study for use in optoelectronics. Methylammonium and formamidinium lead iodide show impressive performance as photovoltaic materials; a premise that has spurred investigations into light-emitting devices and photodetectors. Herein, the optical and electrical material properties of organometal halide perovskites are reviewed. An overview is given on how the material composition and morphology are tied to these properties, and how these properties ultimately affect device performance. Material attributes and techniques used to estimate them are analyzed for different perovskite materials, with a particular focus on the bandgap, mobility, diffusion length, carrier lifetime, and trap-state density.

  11. Smart Optoelectronic Sensors and Intelligent Sensor Systems

    Directory of Open Access Journals (Sweden)

    Sergey Y. YURISH

    2012-03-01

    Full Text Available Light-to-frequency converters are widely used in various optoelectronic sensor systems. However, a further frequency-to-digital conversion is a bottleneck in such systems due to a broad frequency range of light-to-frequency converters’ outputs. This paper describes an effective OEM design approach, which can be used for smart and intelligent sensor systems design. The design is based on novel, multifunctional integrated circuit of Universal Sensors & Transducers Interface especially designed for such sensor applications. Experimental results have confirmed an efficiency of this approach and high metrological performances.

  12. Physics of photonic devices

    CERN Document Server

    Chuang, Shun Lien

    2009-01-01

    The most up-to-date book available on the physics of photonic devices This new edition of Physics of Photonic Devices incorporates significant advancements in the field of photonics that have occurred since publication of the first edition (Physics of Optoelectronic Devices). New topics covered include a brief history of the invention of semiconductor lasers, the Lorentz dipole method and metal plasmas, matrix optics, surface plasma waveguides, optical ring resonators, integrated electroabsorption modulator-lasers, and solar cells. It also introduces exciting new fields of research such as:

  13. Optoelectronic pH Meter: Further Details

    Science.gov (United States)

    Jeevarajan, Antony S.; Anderson, Mejody M.; Macatangay, Ariel V.

    2009-01-01

    A collection of documents provides further detailed information about an optoelectronic instrument that measures the pH of an aqueous cell-culture medium to within 0.1 unit in the range from 6.5 to 7.5. The instrument at an earlier stage of development was reported in Optoelectronic Instrument Monitors pH in a Culture Medium (MSC-23107), NASA Tech Briefs, Vol. 28, No. 9 (September 2004), page 4a. To recapitulate: The instrument includes a quartz cuvette through which the medium flows as it is circulated through a bioreactor. The medium contains some phenol red, which is an organic pH-indicator dye. The cuvette sits between a light source and a photodetector. [The light source in the earlier version comprised red (625 nm) and green (558 nm) light-emitting diodes (LEDs); the light source in the present version comprises a single green- (560 nm)-or-red (623 nm) LED.] The red and green are repeatedly flashed in alternation. The responses of the photodiode to the green and red are processed electronically to obtain the ratio between the amounts of green and red light transmitted through the medium. The optical absorbance of the phenol red in the green light varies as a known function of pH. Hence, the pH of the medium can be calculated from the aforesaid ratio.

  14. Optoelectronic iron detectors for pharmaceutical flow analysis.

    Science.gov (United States)

    Rybkowska, Natalia; Koncki, Robert; Strzelak, Kamil

    2017-10-25

    Compact flow-through optoelectronic detectors fabricated by pairing of light emitting diodes have been applied for development of economic flow analysis systems dedicated for iron ions determination. Three analytical methods with different chromogens selectively recognizing iron ions have been compared. Ferrozine and ferene S based methods offer higher sensitivity and slightly lower detection limits than method with 1,10-phenantroline, but narrower ranges of linear response. Each system allows detection of iron in micromolar range of concentration with comparable sample throughput (20 injections per hour). The developed flow analysis systems have been successfully applied for determination of iron in diet supplements. The utility of developed analytical systems for iron release studies from drug formulations has also been demonstrated. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Optoelectronic circuits in nanometer CMOS technology

    CERN Document Server

    Atef, Mohamed

    2016-01-01

    This book describes the newest implementations of integrated photodiodes fabricated in nanometer standard CMOS technologies. It also includes the required fundamentals, the state-of-the-art, and the design of high-performance laser drivers, transimpedance amplifiers, equalizers, and limiting amplifiers fabricated in nanometer CMOS technologies. This book shows the newest results for the performance of integrated optical receivers, laser drivers, modulator drivers and optical sensors in nanometer standard CMOS technologies. Nanometer CMOS technologies rapidly advanced, enabling the implementation of integrated optical receivers for high data rates of several Giga-bits per second and of high-pixel count optical imagers and sensors. In particular, low cost silicon CMOS optoelectronic integrated circuits became very attractive because they can be extensively applied to short-distance optical communications, such as local area network, chip-to-chip and board-to-board interconnects as well as to imaging and medical...

  16. Seeing smells: development of an optoelectronic nose

    Directory of Open Access Journals (Sweden)

    Kenneth S. Suslick

    2007-06-01

    Full Text Available The development of an array of chemically-responsive dyes on a porous membrane and in its use as a general sensor for odors and volatile organic compounds (VOCs is reviewed. These colorimetric sensor arrays (CSA act as an "optoelectronic nose" by using an array of multiple dyes whose color changes are based on the full range of intermolecular interactions. The CSA is digitally imaged before and after exposure and the resulting difference map provides a digital fingerprint for any VOC or mixture of odorants. The result is an enormous increase in discriminatory power among odorants compared to prior electronic nose technologies. For the detection of biologically important analytes, including amines, carboxylic acids, and thiols, high sensitivities (ppbv have been demonstrated. The array is essentially non-responsive to changes in humidity due to the hydrophobicity of the dyes and membrane.

  17. Investigation of mixed saliva by optoelectronic methods

    Science.gov (United States)

    Savchenko, Ekaterina; Nepomnyashchaya, Elina; Baranov, Maksim; Velichko, Elena; Aksenov, Evgenii; Bogomaz, Tatyana

    2018-04-01

    At present, saliva and its properties are being actively studied. Human saliva is a unique biological material that has potential in clinical practice. A detailed analysis of the characteristics and properties of saliva is relevant for diagnostic purposes. In this paper, the properties and characteristics of saliva are studied using optoelectronic methods: dynamic light scattering, electrophoretic light scattering and optical microscopy. Mixed saliva from a healthy patient and patient with diabetes mellitus type 2 was used as an object of the study. The dynamics of the behavior of a healthy and patient with diabetes mellitus type 2 is visible according to the results obtained. All three methods confirm hypothesis of structural changes in mixed saliva in the disease of diabetes mellitus type 2.

  18. Design of a high-resolution optoelectronic retinal prosthesis.

    Science.gov (United States)

    Palanker, Daniel; Vankov, Alexander; Huie, Phil; Baccus, Stephen

    2005-03-01

    It has been demonstrated that electrical stimulation of the retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. However, current retinal implants provide very low resolution (just a few electrodes), whereas at least several thousand pixels would be required for functional restoration of sight. This paper presents the design of an optoelectronic retinal prosthetic system with a stimulating pixel density of up to 2500 pix mm(-2) (corresponding geometrically to a maximum visual acuity of 20/80). Requirements on proximity of neural cells to the stimulation electrodes are described as a function of the desired resolution. Two basic geometries of sub-retinal implants providing required proximity are presented: perforated membranes and protruding electrode arrays. To provide for natural eye scanning of the scene, rather than scanning with a head-mounted camera, the system operates similar to 'virtual reality' devices. An image from a video camera is projected by a goggle-mounted collimated infrared LED-LCD display onto the retina, activating an array of powered photodiodes in the retinal implant. The goggles are transparent to visible light, thus allowing for the simultaneous use of remaining natural vision along with prosthetic stimulation. Optical delivery of visual information to the implant allows for real-time image processing adjustable to retinal architecture, as well as flexible control of image processing algorithms and stimulation parameters.

  19. Transferrable monolithic III-nitride photonic circuit for multifunctional optoelectronics

    Science.gov (United States)

    Shi, Zheng; Gao, Xumin; Yuan, Jialei; Zhang, Shuai; Jiang, Yan; Zhang, Fenghua; Jiang, Yuan; Zhu, Hongbo; Wang, Yongjin

    2017-12-01

    A monolithic III-nitride photonic circuit with integrated functionalities was implemented by integrating multiple components with different functions into a single chip. In particular, the III-nitride-on-silicon platform is used as it integrates a transmitter, a waveguide, and a receiver into a suspended III-nitride membrane via a wafer-level procedure. Here, a 0.8-mm-diameter suspended device architecture is directly transferred from silicon to a foreign substrate by mechanically breaking the support beams. The transferred InGaN/GaN multiple-quantum-well diode (MQW-diode) exhibits a turn-on voltage of 2.8 V with a dominant electroluminescence peak at 453 nm. The transmitter and receiver share an identical InGaN/GaN MQW structure, and the integrated photonic circuit inherently works for on-chip power monitoring and in-plane visible light communication. The wire-bonded monolithic photonic circuit on glass experimentally demonstrates in-plane data transmission at 120 Mb/s, paving the way for diverse applications in intelligent displays, in-plane light communication, flexible optical sensors, and wearable III-nitride optoelectronics.

  20. Prospects of III-nitride optoelectronics grown on Si

    International Nuclear Information System (INIS)

    Zhu, D; Wallis, D J; Humphreys, C J

    2013-01-01

    The use of III-nitride-based light-emitting diodes (LEDs) is now widespread in applications such as indicator lamps, display panels, backlighting for liquid-crystal display TVs and computer screens, traffic lights, etc. To meet the huge market demand and lower the manufacturing cost, the LED industry is moving fast from 2 inch to 4 inch and recently to 6 inch wafer sizes. Although Al 2 O 3 (sapphire) and SiC remain the dominant substrate materials for the epitaxy of nitride LEDs, the use of large Si substrates attracts great interest because Si wafers are readily available in large diameters at low cost. In addition, such wafers are compatible with existing processing lines for 6 inch and larger wafers commonly used in the electronics industry. During the last decade, much exciting progress has been achieved in improving the performance of GaN-on-Si devices. In this contribution, the status and prospects of III-nitride optoelectronics grown on Si substrates are reviewed. The issues involved in the growth of GaN-based LED structures on Si and possible solutions are outlined, together with a brief introduction to some novel in situ and ex situ monitoring/characterization tools, which are especially useful for the growth of GaN-on-Si structures. (review article)

  1. Design of a high-resolution optoelectronic retinal prosthesis

    Science.gov (United States)

    Palanker, Daniel; Vankov, Alexander; Huie, Phil; Baccus, Stephen

    2005-03-01

    It has been demonstrated that electrical stimulation of the retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. However, current retinal implants provide very low resolution (just a few electrodes), whereas at least several thousand pixels would be required for functional restoration of sight. This paper presents the design of an optoelectronic retinal prosthetic system with a stimulating pixel density of up to 2500 pix mm-2 (corresponding geometrically to a maximum visual acuity of 20/80). Requirements on proximity of neural cells to the stimulation electrodes are described as a function of the desired resolution. Two basic geometries of sub-retinal implants providing required proximity are presented: perforated membranes and protruding electrode arrays. To provide for natural eye scanning of the scene, rather than scanning with a head-mounted camera, the system operates similar to 'virtual reality' devices. An image from a video camera is projected by a goggle-mounted collimated infrared LED-LCD display onto the retina, activating an array of powered photodiodes in the retinal implant. The goggles are transparent to visible light, thus allowing for the simultaneous use of remaining natural vision along with prosthetic stimulation. Optical delivery of visual information to the implant allows for real-time image processing adjustable to retinal architecture, as well as flexible control of image processing algorithms and stimulation parameters.

  2. Fully coupled opto-electronic modelling of organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Reinke, Nils A.; Haeusermann, Roger; Huber, Evelyne; Moos, Michael [ZHAW, Institute of Comp. Physics (Germany); Flatz, Thomas [Fluxim AG (Switzerland); Ruhstaller, Beat [ZHAW, Institute of Comp. Physics (Germany); Fluxim AG (Switzerland)

    2009-07-01

    Record solar power conversion efficiencies of up to 5.5 % for single junction organic solar cells (OSC) are encouraging but still inferior to values of inorganic solar cells. For further progress, a detailed analysis of the mechanisms that limit the external quantum efficiency is crucial. It is widely believed that the device physics of OSCs can be reduced to the processes, which take place at the donor/acceptor-interface. Neglecting transport, trapping and ejection of charge carriers at the electrodes raises the question of the universality of such a simplification. In this study we present a fully coupled opto-electronic simulator, which calculates the spatial and spectral photon flux density inside the OSC, the formation of the charge transfer state and its dissociation into free charge carriers. Our simulator solves the drift- diffusion equations for the generated charge carriers as well as their ejection at the electrodes. Our results are in good agreement with both steady-state and transient OSC characteristics. We address the influence of physical quantities such as the optical properties, film-thicknesses, the recombination rate and charge carrier mobilities on performance figures. For instance the short circuit current can be enhanced by 15% to 25% when using a silver instead of an aluminium cathode. Our simulations lead to rules of thumb, which help to optimise a given OSC structure.

  3. Flexible Synthetic Semiconductor Applied in Optoelectronic Organic Sensor

    Directory of Open Access Journals (Sweden)

    Andre F. S. Guedes

    2017-06-01

    Full Text Available The synthesis and application of new nanostructured organic materials, for the development of technology based on organic devices, have taken great interest from the scientific community. The greatest interest in studying organic semiconductor materials has been connected to its already known potential applications, such as: batteries, organic solar cells, flexible organic solar cells, organic light emitting diodes, organic sensors and others. Phototherapy makes use of different radiation sources, and the treatment of hyperbilirubinemia the most common therapeutic intervention occurs in the neonatal period. In this work we developed an organic optoelectronic sensor capable of detecting and determining the radiation dose rate emitted by the radiation source of neonatal phototherapy equipment. The sensors were developed using optically transparent substrate with Nanostructured thin film layers of Poly(9-Vinylcarbazole covered by a layer of Poly(P-Phenylene Vinylene. The samples were characterized by UV-Vis Spectroscopy, Electrical Measurements and SEM. With the results obtained from this study can be developed dosimeters organics to the neonatal phototherapy equipment.

  4. Size-tunable band alignment and optoelectronic properties of transition metal dichalcogenide van der Waals heterostructures

    Science.gov (United States)

    Zhao, Yipeng; Yu, Wangbing; Ouyang, Gang

    2018-01-01

    2D transition metal dichalcogenide (TMDC)-based heterostructures exhibit several fascinating properties that can address the emerging market of energy conversion and storage devices. Current achievements show that the vertical stacked TMDC heterostructures can form type II band alignment and possess significant optoelectronic properties. However, a detailed analytical understanding of how to quantify the band alignment and band offset as well as the optimized power conversion efficiency (PCE) is still lacking. Herein, we propose an analytical model to exhibit the PCEs of TMDC van der Waals (vdW) heterostructures and explore the intrinsic mechanism of photovoltaic conversion based on the detailed balance principle and atomic-bond-relaxation correlation mechanism. We find that the PCE of monolayer MoS2/WSe2 can be up to 1.70%, and that of the MoS2/WSe2 vdW heterostructures increases with thickness, owing to increasing optical absorption. Moreover, the results are validated by comparing them with the available evidence, providing realistic efficiency targets and design principles. Highlights • Both electronic and optoelectronic models are developed for vertical stacked MoS2/WSe2 heterostructures. • The underlying mechanism on size effect of electronic and optoelectronic properties for vertical stacked MoS2/WSe2 heterostructures is clarified. • The macroscopically measurable quantities and the microscopical bond identities are connected.

  5. Two-Dimensional CH₃NH₃PbI₃ Perovskite: Synthesis and Optoelectronic Application.

    Science.gov (United States)

    Liu, Jingying; Xue, Yunzhou; Wang, Ziyu; Xu, Zai-Quan; Zheng, Changxi; Weber, Bent; Song, Jingchao; Wang, Yusheng; Lu, Yuerui; Zhang, Yupeng; Bao, Qiaoliang

    2016-03-22

    Hybrid organic-inorganic perovskite materials have received substantial research attention due to their impressively high performance in photovoltaic devices. As one of the oldest functional materials, it is intriguing to explore the optoelectronic properties in perovskite after reducing it into a few atomic layers in which two-dimensional (2D) confinement may get involved. In this work, we report a combined solution process and vapor-phase conversion method to synthesize 2D hybrid organic-inorganic perovskite (i.e., CH3NH3PbI3) nanocrystals as thin as a single unit cell (∼1.3 nm). High-quality 2D perovskite crystals have triangle and hexagonal shapes, exhibiting tunable photoluminescence while the thickness or composition is changed. Due to the high quantum efficiency and excellent photoelectric properties in 2D perovskites, a high-performance photodetector was demonstrated, in which the current can be enhanced significantly by shining 405 and 532 nm lasers, showing photoresponsivities of 22 and 12 AW(-1) with a voltage bias of 1 V, respectively. The excellent optoelectronic properties make 2D perovskites building blocks to construct 2D heterostructures for wider optoelectronic applications.

  6. Si-Based Germanium Tin Semiconductor Lasers for Optoelectronic Applications

    Science.gov (United States)

    Al-Kabi, Sattar H. Sweilim

    Silicon-based materials and optoelectronic devices are of great interest as they could be monolithically integrated in the current Si complementary metal-oxide-semiconductor (CMOS) processes. The integration of optoelectronic components on the CMOS platform has long been limited due to the unavailability of Si-based laser sources. A Si-based monolithic laser is highly desirable for full integration of Si photonics chip. In this work, Si-based germanium-tin (GeSn) lasers have been demonstrated as direct bandgap group-IV laser sources. This opens a completely new avenue from the traditional III-V integration approach. In this work, the material and optical properties of GeSn alloys were comprehensively studied. The GeSn films were grown on Ge-buffered Si substrates in a reduced pressure chemical vapor deposition system with low-cost SnCl4 and GeH4 precursors. A systematic study was done for thin GeSn films (thickness 400 nm) with Sn composition 5 to 17.5%. The room temperature photoluminescence (PL) spectra were measured that showed a gradual shift of emission peaks towards longer wavelength as Sn composition increases. Strong PL intensity and low defect density indicated high material quality. Moreover, the PL study of n-doped samples showed bandgap narrowing compared to the unintentionally p-doped (boron) thin films with similar Sn compositions. Finally, optically pumped GeSn lasers on Si with broad wavelength coverage from 2 to 3 mum were demonstrated using high-quality GeSn films with Sn compositions up to 17.5%. The achieved maximum Sn composition of 17.5% broke the acknowledged Sn incorporation limit using similar deposition chemistry. The highest lasing temperature was measured at 180 K with an active layer thickness as thin as 270 nm. The unprecedented lasing performance is due to the achievement of high material quality and a robust fabrication process. The results reported in this work show a major advancement towards Si-based electrically pumped mid

  7. Stereoscopic construction and practice of optoelectronic technology textbook

    Science.gov (United States)

    Zhou, Zigang; Zhang, Jinlong; Wang, Huili; Yang, Yongjia; Han, Yanling

    2017-08-01

    It is a professional degree course textbook for the Nation-class Specialty—Optoelectronic Information Science and Engineering, and it is also an engineering practice textbook for the cultivation of photoelectric excellent engineers. The book seeks to comprehensively introduce the theoretical and applied basis of optoelectronic technology, and it's closely linked to the current development of optoelectronic industry frontier and made up of following core contents, including the laser source, the light's transmission, modulation, detection, imaging and display. At the same time, it also embodies the features of the source of laser, the transmission of the waveguide, the electronic means and the optical processing methods.

  8. Carbon dots—Emerging light emitters for bioimaging, cancer therapy and optoelectronics

    KAUST Repository

    Hola, Katerina; Zhang, Yu; Wang, Yu; Giannelis, Emmanuel P.; Zboril, Radek; Rogach, Andrey L.

    2014-01-01

    © 2014 Elsevier Ltd. All rights reserved. Carbon dots represent an emerging class of fluorescent materials and provide a broad application potential in various fields of biomedicine and optoelectronics. In this review, we introduce various synthetic strategies and basic photoluminescence properties of carbon dots, and then address their advanced in vitro and in vivo bioapplications including cell imaging, photoacoustic imaging, photodynamic therapy and targeted drug delivery. We further consider the applicability of carbon dots as components of light emitting diodes, which include carbon dot based electroluminescence, optical down-conversion, and hybrid plasmonic devices. The review concludes with an outlook towards future developments of these emerging light-emitting materials.

  9. Carbon dots—Emerging light emitters for bioimaging, cancer therapy and optoelectronics

    KAUST Repository

    Hola, Katerina

    2014-10-01

    © 2014 Elsevier Ltd. All rights reserved. Carbon dots represent an emerging class of fluorescent materials and provide a broad application potential in various fields of biomedicine and optoelectronics. In this review, we introduce various synthetic strategies and basic photoluminescence properties of carbon dots, and then address their advanced in vitro and in vivo bioapplications including cell imaging, photoacoustic imaging, photodynamic therapy and targeted drug delivery. We further consider the applicability of carbon dots as components of light emitting diodes, which include carbon dot based electroluminescence, optical down-conversion, and hybrid plasmonic devices. The review concludes with an outlook towards future developments of these emerging light-emitting materials.

  10. Optoelectronic insights into the photovoltaic losses from photocurrent, voltage, and energy perspectives

    Science.gov (United States)

    Shang, Aixue; An, Yidan; Ma, Dong; Li, Xiaofeng

    2017-08-01

    Photocurrent and voltage losses are the fundamental limitations for improving the efficiency of photovoltaic devices. It is indeed that a comprehensive and quantitative differentiation of the performance degradation in solar cells will promote the understanding of photovoltaic physics as well as provide a useful guidance to design highly-efficient and cost-effective solar cells. Based on optoelectronic simulation that addresses electromagnetic and carrier-transport responses in a coupled finite-element method, we report a detailed quantitative analysis of photocurrent and voltage losses in solar cells. We not only concentrate on the wavelength-dependent photocurrent loss, but also quantify the variations of photocurrent and operating voltage under different forward electrical biases. Further, the device output power and power losses due to carrier recombination, thermalization, Joule heat, and Peltier heat are studied through the optoelectronic simulation. The deep insight into the gains and losses of the photocurrent, voltage, and energy will contribute to the accurate clarifications of the performance degradation of photovoltaic devices, enabling a better control of the photovoltaic behaviors for high performance.

  11. Temperature-Induced Lattice Relaxation of Perovskite Crystal Enhances Optoelectronic Properties and Solar Cell Performance

    KAUST Repository

    Banavoth, Murali

    2016-12-14

    Hybrid organic-inorganic perovskite crystals have recently become one of the most important classes of photoactive materials in the solar cell and optoelectronic communities. Albeit improvements have focused on state-of-the-art technology including various fabrication methods, device architectures, and surface passivation, progress is yet to be made in understanding the actual operational temperature on the electronic properties and the device performances. Therefore, the substantial effect of temperature on the optoelectronic properties, charge separation, charge recombination dynamics, and photoconversion efficiency are explored. The results clearly demonstrated a significant enhancement in the carrier mobility, photocurrent, charge carrier lifetime, and solar cell performance in the 60 ± 5 °C temperature range. In this temperature range, perovskite crystal exhibits a highly symmetrical relaxed cubic structure with well-aligned domains that are perpendicular to a principal axis, thereby remarkably improving the device operation. This finding provides a new key variable component and paves the way toward using perovskite crystals in highly efficient photovoltaic cells.

  12. Comprehensive study of the influence of different environments on degradation processes in F8BT: Correlating optoelectronic properties with Raman measurements

    International Nuclear Information System (INIS)

    Linde, Sivan; Shikler, Rafi

    2013-01-01

    There is a growing interest in conjugated polymers from both industrial and academic points of views. The reasons are their tunable optoelectronic properties, ease of production, and excellent mechanical properties. However, the ease with which their optoelectronic properties are tunable make devices based on them prone to fast degradation and therefore, short life time. The issue of degradation of organic based optoelectronic devices is the topic of many ongoing researches. However, much less attention is given to degradation processes of the individual components of the devices and their dependence on the environmental conditions. In this work, we report on the degradation of a film of a polyfluorene block copolymer F8BT that is used in a variety of optoelectronic devices under different environments: Sun exposure, heating, and UV exposure in inert and ambient conditions. Degradation was observed in most of the optoelectronic properties of the film. Topographic measurements did not show observable changes of the film morphology following degradation. However, Raman spectroscopy measurements show changes that indicate degradation in one of the building blocks of the copolymer that is associated with electron's conduction. The absolute value of the correlation coefficient between the decrease in the Raman signal and the decrease in the optoelectronic properties is larger than 0.95 under sun exposure it is larger than 0.8 under all other ambient exposures and smaller than 0.65 under inert conditions. These results support the assumption that Oxygen, not necessarily through photo-oxidation, and also water play an important role in the degradation process and indicate the part of the polymer that is most susceptible to degradation

  13. Compound semiconductor device modelling

    CERN Document Server

    Miles, Robert

    1993-01-01

    Compound semiconductor devices form the foundation of solid-state microwave and optoelectronic technologies used in many modern communication systems. In common with their low frequency counterparts, these devices are often represented using equivalent circuit models, but it is often necessary to resort to physical models in order to gain insight into the detailed operation of compound semiconductor devices. Many of the earliest physical models were indeed developed to understand the 'unusual' phenomena which occur at high frequencies. Such was the case with the Gunn and IMPATI diodes, which led to an increased interest in using numerical simulation methods. Contemporary devices often have feature sizes so small that they no longer operate within the familiar traditional framework, and hot electron or even quantum­ mechanical models are required. The need for accurate and efficient models suitable for computer aided design has increased with the demand for a wider range of integrated devices for operation at...

  14. Optoelectronic and nonlinear optical processes in low dimensional ...

    Indian Academy of Sciences (India)

    Optoelectronic process; nonlinear optical process; semiconductor. Quest for ever faster and intelligent information processing technologies has sparked ..... Schematic energy level diagram for the proposed 4-level model. States other than the.

  15. Optoelectronic properties of doped hydrothermal ZnO thin films

    KAUST Repository

    Mughal, Asad J.; Carberry, Benjamin; Oh, Sang Ho; Myzaferi, Anisa; Speck, James S.; Nakamura, Shuji; DenBaars, Steven P.

    2017-01-01

    , or In were evaluated for their optoelectronic properties. Inductively coupled plasma atomic emission spectroscopy was used to determine the concentration of dopants within the ZnO films. While Al and Ga-doped films showed linear incorporation rates

  16. Basic opto-electronics on silicon for sensor applications

    NARCIS (Netherlands)

    Joppe, J.L.; Bekman, H.H.P.Th.; de Krijger, A.J.T.; Albers, H.; Chalmers, J.; Chalmers, J.D.; Holleman, J.; Ikkink, T.J.; Ikkink, T.; van Kranenburg, H.; Zhou, M.-J.; Zhou, Ming-Jiang; Lambeck, Paul

    1994-01-01

    A general platform for integrated opto-electronic sensor systems on silicon is proposed. The system is based on a hybridly integrated semiconductor laser, ZnO optical waveguides and monolithic photodiodes and electronic circuiry.

  17. Advanced Optoelectronic Components for All-Optical Networks

    National Research Council Canada - National Science Library

    Shapiro, Jeffrey H

    2002-01-01

    Under APOSR Grant F49620-96-1-0126, 'Advanced Optoelectronic Components for All-Optical Networks', we have worked to develop key technologies and components to substantially improve the performance...

  18. Integrated Production of Ultra-Low Defect GaN Films and Devices for High-Power Amplifiers, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — High quality GaN epitaxial films are key to current efforts for development of both high-power/high-speed electronic devices and optoelectronic devices. In fact,...

  19. Integrated Production of Ultra-Low Defect GaN Films and Devices for High-Power Amplifiers, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — High quality GaN epitaxial films are one of the keys to current efforts for development of both high-power/high-speed electronic devices and optoelectronic devices....

  20. Integrated Optoelectronic Networks for Application-Driven Multicore Computing

    Science.gov (United States)

    2017-05-08

    AFRL-AFOSR-VA-TR-2017-0102 Integrated Optoelectronic Networks for Application- Driven Multicore Computing Sudeep Pasricha COLORADO STATE UNIVERSITY...AND SUBTITLE Integrated Optoelectronic Networks for Application-Driven Multicore Computing 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-13-1-0110 5c...and supportive materials with innovative architectural designs that integrate these components according to system-wide application needs. 15

  1. Software for Use with Optoelectronic Measuring Tool

    Science.gov (United States)

    Ballard, Kim C.

    2004-01-01

    A computer program has been written to facilitate and accelerate the process of measurement by use of the apparatus described in "Optoelectronic Tool Adds Scale Marks to Photographic Images" (KSC-12201). The tool contains four laser diodes that generate parallel beams of light spaced apart at a known distance. The beams of light are used to project bright spots that serve as scale marks that become incorporated into photographic images (including film and electronic images). The sizes of objects depicted in the images can readily be measured by reference to the scale marks. The computer program is applicable to a scene that contains the laser spots and that has been imaged in a square pixel format that can be imported into a graphical user interface (GUI) generated by the program. It is assumed that the laser spots and the distance(s) to be measured all lie in the same plane and that the plane is perpendicular to the line of sight of the camera used to record the image

  2. Release strategies for making transferable semiconductor structures, devices and device components

    Science.gov (United States)

    Rogers, John A; Nuzzo, Ralph G; Meitl, Matthew; Ko, Heung Cho; Yoon, Jongseung; Menard, Etienne; Baca, Alfred J

    2014-11-25

    Provided are methods for making a device or device component by providing a multilayer structure having a plurality of functional layers and a plurality of release layers and releasing the functional layers from the multilayer structure by separating one or more of the release layers to generate a plurality of transferable structures. The transferable structures are printed onto a device substrate or device component supported by a device substrate. The methods and systems provide means for making high-quality and low-cost photovoltaic devices, transferable semiconductor structures, (opto-)electronic devices and device components.

  3. Mild Conditions for Deuteration of Primary and Secondary Arylamines for the Synthesis of Deuterated Optoelectronic Organic Molecules

    Directory of Open Access Journals (Sweden)

    Anwen M. Krause-Heuer

    2014-11-01

    Full Text Available Deuterated arylamines demonstrate great potential for use in optoelectronic devices, but their widespread utility requires a method for large-scale synthesis. The incorporation of these deuterated materials into optoelectronic devices also provides the opportunity for studies of the functioning device using neutron reflectometry based on the difference in the scattering length density between protonated and deuterated compounds. Here we report mild deuteration conditions utilising standard laboratory glassware for the deuteration of: diphenylamine, N-phenylnaphthylamine, N-phenyl-o-phenylenediamine and 1-naphthylamine (via H/D exchange in D2O at 80 °C, catalysed by Pt/C and Pd/C. These conditions were not successful in the deuteration of triphenylamine or N,N-dimethylaniline, suggesting that these mild conditions are not suitable for the deuteration of tertiary arylamines, but are likely to be applicable for the deuteration of other primary and secondary arylamines. The deuterated arylamines can then be used for synthesis of larger organic molecules or polymers with optoelectronic applications.

  4. Organic ferroelectric opto-electronic memories

    NARCIS (Netherlands)

    Asadi, K.; Li, M.; Blom, P.W.M.; Kemerink, M.; Leeuw, D.M. de

    2011-01-01

    Memory is a prerequisite for many electronic devices. Organic non-volatile memory devices based on ferroelectricity are a promising approach towards the development of a low-cost memory technology based on a simple cross-bar array. In this review article we discuss the latest developments in this

  5. Integrated optics and optoelectronics II; Proceedings of the Meeting, San Jose, CA, Sept. 17-19, 1990

    International Nuclear Information System (INIS)

    Wong, Ka-Kha

    1991-01-01

    The present volume on integrated optics and optoelectronics discusses proton- and ion-exchange technologies, radiation effects on GaAs optical system FET devices and on the dynamical behavior of LiNbO3 switching devices, advanced lightwave components and concepts, advanced optical interconnects concepts, advanced aircraft and engine control, IOCs for fiber-optic gyroscopes, and commercial integrated optical devices. Attention is given to integrated optical devices for high-data-rate serial-to-parallel conversion, the design of novel integrated optic devices using depressed index waveguides, and a low-loss L-band microwave fiber-optic link for control of a T/R module. Topics addressed include the temperature and modulation dependence of spectral linewidth in distributed Bragg reflector laser diodes, length-minimization design considerations in photonic integrated circuits incorporating directional couplers, and the photochemical formation of polymeric optical waveguides and devices for optical interconnection applications

  6. Optoelectronic Evaluation and Loss Analysis of PEDOT:PSS/Si Hybrid Heterojunction Solar Cells.

    Science.gov (United States)

    Yang, Zhenhai; Fang, Zebo; Sheng, Jiang; Ling, Zhaoheng; Liu, Zhaolang; Zhu, Juye; Gao, Pingqi; Ye, Jichun

    2017-12-01

    The organic/silicon (Si) hybrid heterojunction solar cells (HHSCs) have attracted considerable attention due to their potential advantages in high efficiency and low cost. However, as a newly arisen photovoltaic device, its current efficiency is still much worse than commercially available Si solar cells. Therefore, a comprehensive and systematical optoelectronic evaluation and loss analysis on this HHSC is therefore highly necessary to fully explore its efficiency potential. Here, a thoroughly optoelectronic simulation is provided on a typical planar polymer poly (3,4-ethylenedioxy thiophene):polystyrenesulfonate (PEDOT:PSS)/Si HHSC. The calculated spectra of reflection and external quantum efficiency (EQE) match well with the experimental results in a full-wavelength range. The losses in current density, which are contributed by both optical losses (i.e., reflection, electrode shield, and parasitic absorption) and electrical recombination (i.e., the bulk and surface recombination), are predicted via carefully addressing the electromagnetic and carrier-transport processes. In addition, the effects of Si doping concentrations and rear surface recombination velocities on the device performance are fully investigated. The results drawn in this study are beneficial to the guidance of designing high-performance PEDOT:PSS/Si HHSCs.

  7. Thickness, morphology, and optoelectronic characteristics of pristine and surfactant-modified DNA thin films

    International Nuclear Information System (INIS)

    Arasu, Velu; Reddy Dugasani, Sreekantha; Son, Junyoung; Gnapareddy, Bramaramba; Ha Park, Sung; Jeon, Sohee; Jeong, Jun-Ho

    2017-01-01

    Although the preparation of DNA thin films with well-defined thicknesses controlled by simple physical parameters is crucial for constructing efficient, stable, and reliable DNA-based optoelectronic devices and sensors, it has not been comprehensively studied yet. Here, we construct DNA and surfactant-modified DNA thin films by drop-casting and spin-coating techniques. The DNA thin films formed with different control parameters, such as drop-volume and spin-speed at given DNA concentrations, exhibit characteristic thickness, surface roughness, surface potential, and absorbance, which are measured by a field emission scanning electron microscope, a surface profilometer, an ellipsometer, an atomic force microscope, a Kelvin probe force microscope, and an UV–visible spectroscope. From the observations, we realized that thickness significantly affects the physical properties of DNA thin films. This comprehensive study of thickness-dependent characteristics of DNA and surfactant-modified DNA thin films provides insight into the choice of fabrication techniques in order for the DNA thin films to have desired physical characteristics in further applications, such as optoelectronic devices and sensors. (paper)

  8. Optoelectronic properties of transparent p-type semiconductor Cu{sub x}S thin films

    Energy Technology Data Exchange (ETDEWEB)

    Parreira, P.; Valente, J. [ICEMS, IST-UTL, Lisboa (Portugal); Lavareda, G. [Departamento de Fisica, IST-UTL, Lisboa (Portugal); Nunes, F.T. [Departamento de Ciencia dos Materiais, FCT-UNL, Caparica (Portugal); Amaral, A. [Departamento de Fisica, IST-UTL, Lisboa (Portugal); ICEMS, IST-UTL, Lisboa (Portugal); Carvalho, C.N. de [Departamento de Ciencia dos Materiais, FCT-UNL, Caparica (Portugal); ICEMS, IST-UTL, Lisboa (Portugal)

    2010-07-15

    Nowadays, among the available transparent semiconductors for device use, the great majority (if not all) have n-type conductivity. The fabrication of a transparent p-type semiconductor with good optoelectronic properties (comparable to those of n-type: InO{sub x}, ITO, ZnO{sub x} or FTO) would significantly broaden the application field of thin films. However, until now no material has yet presented all the required properties. Cu{sub 2}S is a p-type narrow-band-gap material with an average optical transmittance of about 60% in the visible range for 50 nm thick films. However, due to its high conductivity at room temperature, 10 nm in thickness seems to be appropriate for device use. Cu{sub 2}S thin films with 10 nm in thickness have an optical visible transmittance of about 85% rendering them as very good candidates for transparent p-type semiconductors. In this work Cu{sub x}S thin films were deposited on alkali-free (AF) glass by thermal evaporation. The objective was not only the determination of its optoelectronic properties but also the feasibility of an active layer in a p-type thin film transistor. In our Cu{sub x}S thin films, p-type high conductivity with a total visible transmittance of about 50% have been achieved. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  9. The optoelectronic chameleon - GaN-based light emitters from the UV to green

    Energy Technology Data Exchange (ETDEWEB)

    Kneissl, Michael [Institut fuer Festkoerperphysik, Technische Universitaet Berlin (Germany)

    2008-07-01

    Group III-nitrides have evolved into one of the most versatile and important semiconductor materials for optoelectronic devices. GaN-based blue, green and white light emitting diodes have already entered many parts of everyday life and violet lasers are expected to be following soon. However, considering the extraordinary electronic properties and the wide spectral range that is accessible through nitride materials, it appears that it we have just touched the tip of the iceberg. We discuss some of the new fields of research for InAlGaN materials and devices and review progress in the development of near and deep ultraviolet light emitting diodes, as well as growth and optical properties of InN and indium rich InGaN alloys for emitter in the blue-green spectral range and beyond.

  10. Optoelectronic and Photovoltaic Properties of the Air-Stable Organohalide Semiconductor (CH 3 NH 3 ) 3 Bi 2 I 9

    KAUST Repository

    Abulikemu, Mutalifu

    2016-07-14

    Lead halide perovskite materials have shown excellent optoelectronic as well as photovoltaic properties. However, the presence of lead and the chemical instability relegate lead halide perovskites to research applications only. Here, we investigate an emerging lead-free and air stable compound (CH3NH3)3Bi2I9 as a non-toxic potential alternative to lead halide perovskites. We have synthesized thin films, powders and millimeter-scale single crystals of (CH3NH3)3Bi2I9 and investigated their structural and optoelectronic properties. We demonstrate that the degree of crystallinity strongly affects the optoelectronic properties of the material, resulting in significantly different band gaps in polycrystalline thin films and single crystals. Surface photovoltage spectroscopy reveals outstanding photocharge generation in the visible (<700 nm), while transient absorption spectroscopy and space charge limited current measurements point to a long exciton lifetime and a high carrier mobility, respectively, similar to lead halide perovskites, pointing to the remarkable potential of this semiconductor. Photovoltaic devices fabricated using this material yield low power conversion efficiency (PCE) to date, but the PCE is expected to rise with improvements in thin film processing and device engineering.

  11. Preparation, characterization and optoelectronic properties of nanodiamonds doped zinc oxide nanomaterials by a ball milling technique

    Science.gov (United States)

    Ullah, Hameed; Sohail, Muhammad; Malik, Uzma; Ali, Naveed; Bangash, Masroor Ahmad; Nawaz, Mohsan

    2016-07-01

    Zinc oxide (ZnO) is one of the very important metal oxides (MOs) for applications in optoelectronic devices which work in the blue and UV regions. However, to meet the challenges of obtaining ZnO nanomaterials suitable for practical applications, various modifications in physico-chemical properties are highly desirable. One of the ways adopted for altering the properties is to synthesize composite(s) of ZnO with various reinforcements. Here we report on the tuning of optoelectronic properties of ZnO upon doping by nanodiamonds (NDs) using the ball milling technique. A varying weight percent (wt.%) of NDs were ball milled for 2 h with ZnO nanoparticles prepared by a simple precipitation method. The effects of different parameters, the calcination temperature of ZnO, wt.% of NDs and mechanical milling upon the optoelectronic properties of the resulting ZnO-NDs nanocomposites have been investigated. The ZnO-NDs nanocomposites were characterized by IR spectroscopy, powder x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). The UV-vis spectroscopy revealed the alteration in the bandgap energy (Eg ) of ZnO as a function of the calcination temperature of ZnO, changing the concentration of NDs, and mechanical milling of the resulting nanocomposites. The photoluminescence (PL) spectroscopy showed a decrease in the deep level emission (DLE) peaks and an increase in near-band-edge transition peaks as a result of the increasing concentration of NDs. The decrease in DLE and increase in band to band transition peaks were due to the strong interaction between the NDs and the Zn+; consequently, the Zn+ concentration decreased on the interstitial sites.

  12. Practical opto-electronics an illustrated guide for the laboratory

    CERN Document Server

    Protopopov, Vladimir

    2014-01-01

    This book explains how to create opto-electronic systems in a most efficient way, avoiding typical mistakes. It covers light detection techniques, imaging, interferometry, spectroscopy, modulation-demodulation, heterodyning, beam steering, and many other topics common to laboratory applications. The focus is made on self-explanatory figures rather than on words. The book guides the reader through the entire process of creating problem-specific opto-electronic systems, starting from optical source, through beam transportation optical arrangement, to photodetector and data acquisition system. The relevant basics of beam propagation and computer-based raytracing routines are also explained, and sample codes are listed. the book teaches important know-how and practical tricks that are never disclosed in scientific publications.  The book can become the reader's personal adviser in the world of opto-electronics and navigator in the ocean of the market of optical components and systems. Succinct, well-illustrate...

  13. The construction of bilingual teaching of optoelectronic technology

    Science.gov (United States)

    Zhang, Yang; Zhao, Enming; Yang, Fan; Li, Qingbo; Zhu, Zheng; Li, Cheng; Sun, Peng

    2017-08-01

    This paper combines the characteristics of optoelectronic technology with that of bilingual teaching. The course pays attention to integrating theory with practice, and cultivating learners' ability. Reform and exploration have been done in the fields of teaching materials, teaching content, teaching methods, etc. The concrete content mainly includes five parts: selecting teaching materials, establishing teaching syllabus, choosing suitable teaching method, making multimedia courseware and improving the test system, which can arouse students' interest in their study and their autonomous learning ability to provide beneficial references for improving the quality of talents of optoelectronic bilingual courses.

  14. Opto-electronic DNA chip-based integrated card for clinical diagnostics.

    Science.gov (United States)

    Marchand, Gilles; Broyer, Patrick; Lanet, Véronique; Delattre, Cyril; Foucault, Frédéric; Menou, Lionel; Calvas, Bernard; Roller, Denis; Ginot, Frédéric; Campagnolo, Raymond; Mallard, Frédéric

    2008-02-01

    Clinical diagnostics is one of the most promising applications for microfluidic lab-on-a-chip or lab-on-card systems. DNA chips, which provide multiparametric data, are privileged tools for genomic analysis. However, automation of molecular biology protocol and use of these DNA chips in fully integrated systems remains a great challenge. Simplicity of chip and/or card/instrument interfaces is amongst the most critical issues to be addressed. Indeed, current detection systems for DNA chip reading are often complex, expensive, bulky and even limited in terms of sensitivity or accuracy. Furthermore, for liquid handling in the lab-on-cards, many devices use complex and bulky systems, either to directly manipulate fluids, or to ensure pneumatic or mechanical control of integrated valves. All these drawbacks prevent or limit the use of DNA-chip-based integrated systems, for point-of-care testing or as a routine diagnostics tool. We present here a DNA-chip-based protocol integration on a plastic card for clinical diagnostics applications including: (1) an opto-electronic DNA-chip, (2) fluid handling using electrically activated embedded pyrotechnic microvalves with closing/opening functions. We demonstrate both fluidic and electric packaging of the optoelectronic DNA chip without major alteration of its electronical and biological functionalities, and fluid control using novel electrically activable pyrotechnic microvalves. Finally, we suggest a complete design of a card dedicated to automation of a complex biological protocol with a fully electrical fluid handling and DNA chip reading.

  15. Study on optoelectronic properties of Spiro-CN for developing an efficient OLED

    Science.gov (United States)

    Mishra, Ashok Kumar

    2018-05-01

    There are a class of organic molecules and polymers which exhibit semiconductor behavior because of nearly free conjugate π-electrons. Hopping of these electrons in molecules forms different excited singlet and triplet states named as excitons. Some of these organic molecules can be set to emit photons by triplet-singlet excitonic transition via a process called Thermally Activated Delayed Fluorescence (TADF) which is exploited for designing the Organic Light Emitting diode (OLED.) Spiro-CN (spirobifluorene skeletons) Spiro is one of these reported noble metal-free TADF molecules which offers unique optical and electronic properties arising from the efficient transition and reverse intersystem crossing between the lowest singlet (S) and triplet (T) excited states. Its ability to harvest triplet excitons for fluorescence through facilitated reverse intersystem crossing (T→S) could directly impact their properties and performances, which is attractive for a wide variety of low-cost optoelectronic device. In the present study, the Spiro-CN compounds have been taken up for the investigation of various optoelectronic properties including the thermally activated delayed fluorescence (TADF) by using the Koopmans Method and Density Functional Theory. The present study discusses the utility of the Spiro-CN organic semiconductor as a suitable TADF material essential for developing an efficient Organic Light Emitting Diode (OLED).

  16. Controlling microstructure of pentacene derivatives by solution processing: impact of structural anisotropy on optoelectronic properties.

    Science.gov (United States)

    James, David T; Frost, Jarvist M; Wade, Jessica; Nelson, Jenny; Kim, Ji-Seon

    2013-09-24

    The consideration of anisotropic structural properties and their impact on optoelectronic properties in small-molecule thin films is vital to understand the performance of devices incorporating crystalline organic semiconductors. Here we report on the important relationship between structural and optoelectronic anisotropy in aligned, functionalized-pentacene thin films fabricated using the solution-based zone-casting technique. The microstructure of thin films composed of 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) and 6,13-bis(triethylsilylethynyl)pentacene (TES-pentacene) is systematically controlled by varying the casting speed. By controlling the structural alignment, we were able to experimentally decouple, for the first time in these films, an intramolecular absorption transition dipole (at ∼440 nm) oriented close to the pentacene short axis and an intermolecular absorption transition dipole (at ∼695 nm) oriented predominantly along the conjugated pentacene-pentacene core stacking axis (crystallographic a-axis) in both films. Using the intermolecular absorption as a signature for intermolecular delocalization, much higher optical dichroism was obtained in TES-pentacene (16 ± 6) than TIPS-pentacene (3.2 ± 0.1), which was attributed to the 1D packing structure of TES-pentacene compared to the 2D packing structure of TIPS-pentacene. This result was also supported by field-effect mobility anisotropy measurements of the films, with TES-pentacene exhibiting a higher anisotropy (∼21-47, depending on the casting speed) than TIPS-pentacene (∼3-10).

  17. Surface structure, optoelectronic properties and charge transport in ZnO nanocrystal/MDMO-PPV multilayer films.

    Science.gov (United States)

    Lian, Qing; Chen, Mu; Mokhtar, Muhamad Z; Wu, Shanglin; Zhu, Mingning; Whittaker, Eric; O'Brien, Paul; Saunders, Brian R

    2018-05-07

    Blends of semiconducting nanocrystals and conjugated polymers continue to attract major research interest because of their potential applications in optoelectronic devices, such as solar cells, photodetectors and light-emitting diodes. In this study we investigate the surface structure, morphological and optoelectronic properties of multilayer films constructed from ZnO nanocrystals (NCs) and poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV). The effects of layer number and ZnO concentration (C ZnO ) used on the multilayer film properties are investigated. An optimised solvent blend enabled well-controlled layers to be sequentially spin coated and the construction of multilayer films containing six ZnO NC (Z) and MDMO-PPV (M) layers (denoted as (ZM) 6 ). Contact angle data showed a strong dependence on C ZnO and indicated distinct differences in the coverage of MDMO-PPV by the ZnO NCs. UV-visible spectroscopy showed that the MDMO-PPV absorption increased linearly with the number of layers in the films and demonstrates highly tuneable light absorption. Photoluminescence spectra showed reversible quenching as well as a surprising red-shift of the MDMO-PPV emission peak. Solar cells were constructed to probe vertical photo-generated charge transport. The measurements showed that (ZM) 6 devices prepared using C ZnO = 14.0 mg mL -1 had a remarkably high open circuit voltage of ∼800 mV. The device power conversion efficiency was similar to that of a control bilayer device prepared using a much thicker MDMO-PPV layer. The results of this study provide insight into the structure-optoelectronic property relationships of new semiconducting multilayer films which should also apply to other semiconducting NC/polymer combinations.

  18. Handbook of compound semiconductors growth, processing, characterization, and devices

    CERN Document Server

    Holloway, Paul H

    1996-01-01

    This book reviews the recent advances and current technologies used to produce microelectronic and optoelectronic devices from compound semiconductors. It provides a complete overview of the technologies necessary to grow bulk single-crystal substrates, grow hetero-or homoepitaxial films, and process advanced devices such as HBT's, QW diode lasers, etc.

  19. Building devices from colloidal quantum dots.

    Science.gov (United States)

    Kagan, Cherie R; Lifshitz, Efrat; Sargent, Edward H; Talapin, Dmitri V

    2016-08-26

    The continued growth of mobile and interactive computing requires devices manufactured with low-cost processes, compatible with large-area and flexible form factors, and with additional functionality. We review recent advances in the design of electronic and optoelectronic devices that use colloidal semiconductor quantum dots (QDs). The properties of materials assembled of QDs may be tailored not only by the atomic composition but also by the size, shape, and surface functionalization of the individual QDs and by the communication among these QDs. The chemical and physical properties of QD surfaces and the interfaces in QD devices are of particular importance, and these enable the solution-based fabrication of low-cost, large-area, flexible, and functional devices. We discuss challenges that must be addressed in the move to solution-processed functional optoelectronic nanomaterials. Copyright © 2016, American Association for the Advancement of Science.

  20. Flexible manufacturing for photonics device assembly

    Science.gov (United States)

    Lu, Shin-Yee; Pocha, Michael D.; Strand, Oliver T.; Young, K. David

    1994-01-01

    The assembly of photonics devices such as laser diodes, optical modulators, and opto-electronics multi-chip modules (OEMCM), usually requires the placement of micron size devices such as laser diodes, and sub-micron precision attachment between optical fibers and diodes or waveguide modulators (usually referred to as pigtailing). This is a very labor intensive process. Studies done by the opto-electronics (OE) industry have shown that 95 percent of the cost of a pigtailed photonic device is due to the use of manual alignment and bonding techniques, which is the current practice in industry. At Lawrence Livermore National Laboratory, we are working to reduce the cost of packaging OE devices through the use of automation. Our efforts are concentrated on several areas that are directly related to an automated process. This paper will focus on our progress in two of those areas, in particular, an automated fiber pigtailing machine and silicon micro-technology compatible with an automated process.

  1. Divergent synthesis and optoelectronic properties of oligodiacetylene building blocks

    NARCIS (Netherlands)

    Pilzak, G.S.; Lagen, van B.; Sudhölter, E.J.R.; Zuilhof, H.

    2008-01-01

    A new and divergent synthetic route to oligodiacetylene (ODA) building blocks has been developed via Sonogashira reactions under a reductive atmosphere. These central building blocks provide a new way for rapid preparation of long ODAs. In addition, we report on their optoelectronic properties which

  2. Advances in wide bandgap SiC for optoelectronics

    DEFF Research Database (Denmark)

    Ou, Haiyan; Ou, Yiyu; Argyraki, Aikaterini

    2014-01-01

    Silicon carbide (SiC) has played a key role in power electronics thanks to its unique physical properties like wide bandgap, high breakdown field, etc. During the past decade, SiC is also becoming more and more active in optoelectronics thanks to the progress in materials growth and nanofabrication...

  3. Microscopic optoelectronic defectoscopy of solar cells

    Directory of Open Access Journals (Sweden)

    Dallaeva D.

    2013-05-01

    Full Text Available Scanning probe microscopes are powerful tool for micro- or nanoscale diagnostics of defects in crystalline silicon solar cells. Solar cell is a large p-n junction semiconductor device. Its quality is strongly damaged by the presence of defects. If the cell works under low reverse-biased voltage, defects emit a light in visible range. The suggested method combines three different measurements: electric noise measurement, local topography and near-field optical beam induced current and thus provides more complex information. To prove its feasibility, we have selected one defect (truncated pyramid in the sample, which emitted light under low reverse-biased voltage.

  4. Modification of the optoelectronic properties of two-dimensional MoS2 crystals by ultraviolet-ozone treatment

    Science.gov (United States)

    Yang, Hae In; Park, Seonyoung; Choi, Woong

    2018-06-01

    We report the modification of the optoelectronic properties of mechanically-exfoliated single layer MoS2 by ultraviolet-ozone exposure. Photoluminescence emission of pristine MoS2 monotonically decreased and eventually quenched as ultraviolet-ozone exposure time increased from 0 to 10 min. The reduction of photoluminescence emission accompanied reduction of Raman modes, suggesting structural degradation in ultraviolet-ozone exposed MoS2. Analysis with X-ray photoelectron spectroscopy revealed that the formation of Ssbnd O and Mosbnd O bonding increases with ultraviolet-ozone exposure time. Measurement of electrical transport properties of MoS2 in a bottom-gate thin-film transistor configuration suggested the presence of insulating MoO3 after ultraviolet-ozone exposure. These results demonstrate that ultraviolet-ozone exposure can significantly influence the optoelectronic properties of single layer MoS2, providing important implications on the application of MoS2 and other two-dimensional materials into optoelectronic devices.

  5. Optoelectronic Tweezers for Microparticle and Cell Manipulation

    Science.gov (United States)

    Wu, Ming Chiang (Inventor); Chiou, Pei-Yu (Inventor); Ohta, Aaron T. (Inventor)

    2014-01-01

    An optical image-driven light induced dielectrophoresis (DEP) apparatus and method are described which provide for the manipulation of particles or cells with a diameter on the order of 100 micromillimeters or less. The apparatus is referred to as optoelectric tweezers (OET) and provides a number of advantages over conventional optical tweezers, in particular the ability to perform operations in parallel and over a large area without damage to living cells. The OET device generally comprises a planar liquid-filled structure having one or more portions which are photoconductive to convert incoming light to a change in the electric field pattern. The light patterns are dynamically generated to provide a number of manipulation structures that can manipulate single particles and cells or group of particles/cells. The OET preferably includes a microscopic imaging means to provide feedback for the optical manipulation, such as detecting position and characteristics wherein the light patterns are modulated accordingly.

  6. Wide gap semiconductor microwave devices

    International Nuclear Information System (INIS)

    Buniatyan, V V; Aroutiounian, V M

    2007-01-01

    A review of properties of wide gap semiconductor materials such as diamond, diamond-like carbon films, SiC, GaP, GaN and AlGaN/GaN that are relevant to electronic, optoelectronic and microwave applications is presented. We discuss the latest situation and perspectives based on experimental and theoretical results obtained for wide gap semiconductor devices. Parameters are taken from the literature and from some of our theoretical works. The correspondence between theoretical results and parameters of devices is critically analysed. (review article)

  7. p-type ZnS:N nanowires: Low-temperature solvothermal doping and optoelectronic properties

    International Nuclear Information System (INIS)

    Wang, Ming-Zheng; Xie, Wei-Jie; Hu, Han; Yu, Yong-Qiang; Wu, Chun-Yan; Wang, Li; Luo, Lin-Bao

    2013-01-01

    Nitrogen doped p-type ZnS nanowires (NWs) were realized using thermal decomposition of triethylamine at a mild temperature. Field-effect transistors made from individual ZnS:N NWs revealed typical p-type conductivity behavior, with a hole mobility of 3.41 cm 2 V −1 s −1 and a hole concentration of 1.67 × 10 17  cm −3 , respectively. Further analysis found that the ZnS:N NW is sensitive to UV light irradiation with high responsivity, photoconductive gain, and good spectral selectivity. The totality of this study suggests that the solvothermal doping method is highly feasible to dope one dimensional semiconductor nanostructures for optoelectronic devices application

  8. Investigation of the Optoelectronic Properties of Ti-doped Indium Tin Oxide Thin Film

    Directory of Open Access Journals (Sweden)

    Nen-Wen Pu

    2015-09-01

    Full Text Available : In this study, direct-current magnetron sputtering was used to fabricate Ti-doped indium tin oxide (ITO thin films. The sputtering power during the 350-nm-thick thin-film production process was fixed at 100 W with substrate temperatures increasing from room temperature to 500 °C. The Ti-doped ITO thin films exhibited superior thin-film resistivity (1.5 × 10−4 Ω/cm, carrier concentration (4.1 × 1021 cm−3, carrier mobility (10 cm2/Vs, and mean visible-light transmittance (90% at wavelengths of 400–800 nm at a deposition temperature of 400 °C. The superior carrier concentration of the Ti-doped ITO alloys (>1021 cm−3 with a high figure of merit (81.1 × 10−3 Ω−1 demonstrate the pronounced contribution of Ti doping, indicating their high suitability for application in optoelectronic devices.

  9. Investigation of the Optoelectronic Properties of Ti-doped Indium Tin Oxide Thin Film.

    Science.gov (United States)

    Pu, Nen-Wen; Liu, Wei-Sheng; Cheng, Huai-Ming; Hu, Hung-Chun; Hsieh, Wei-Ting; Yu, Hau-Wei; Liang, Shih-Chang

    2015-09-21

    : In this study, direct-current magnetron sputtering was used to fabricate Ti-doped indium tin oxide (ITO) thin films. The sputtering power during the 350-nm-thick thin-film production process was fixed at 100 W with substrate temperatures increasing from room temperature to 500 °C. The Ti-doped ITO thin films exhibited superior thin-film resistivity (1.5 × 10 - ⁴ Ω/cm), carrier concentration (4.1 × 10 21 cm - ³), carrier mobility (10 cm²/Vs), and mean visible-light transmittance (90%) at wavelengths of 400-800 nm at a deposition temperature of 400 °C. The superior carrier concentration of the Ti-doped ITO alloys (>10 21 cm - ³) with a high figure of merit (81.1 × 10 - ³ Ω - ¹) demonstrate the pronounced contribution of Ti doping, indicating their high suitability for application in optoelectronic devices.

  10. Exploration on the training mode of application-oriented talents majoring in optoelectronic information

    Science.gov (United States)

    Lv, Hao; Liu, Aimei; Zhang, Shengyi; Xiao, Yongjun

    2017-08-01

    The optoelectronic information major is a strong theoretical and practical specialty. In view of the problems existing in the application-oriented talents training in the optoelectronic information specialty. Five aspects of the talent cultivation plan, the teaching staff, the teaching content, the practical teaching and the scientific research on the training mode of application-oriented talents majoring in optoelectronic information are putted forward. It is beneficial to the specialty construction of optoelectronic information industry which become close to the development of enterprises, and the depth of the integration of school and enterprise service regional economic optoelectronic information high-end skilled personnel base.

  11. Resonant infrared laser deposition of polymer-nanocomposite materials for optoelectronic applications

    Science.gov (United States)

    Park, Hee K.; Schriver, Kenneth E.; Haglund, Richard F.

    2011-11-01

    Polymers find a number of potentially useful applications in optoelectronic devices. These include both active layers, such as light-emitting polymers and hole-transport layers, and passive layers, such as polymer barrier coatings and light-management films. This paper reports the experimental results for polymer films deposited by resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) and resonant infrared pulsed laser deposition (RIR-PLD) for commercial optoelectronic device applications. In particular, light-management films, such as anti-reflection coatings, require refractive-index engineering of a material. However, refractive indices of polymers fall within a relatively narrow range, leading to major efforts to develop both low- and high-refractive-index polymers. Polymer nanocomposites can expand the range of refractive indices by incorporating low- or high-refractive-index nanoscale materials. RIR-MAPLE is an excellent technique for depositing polymer-nanocomposite films in multilayer structures, which are essential to light-management coatings. In this paper, we report our efforts to engineer the refractive index of a barrier polymer by combining RIR-MAPLE of nanomaterials (for example, high refractive-index TiO2 nanoparticles) and RIR-PLD of host polymer. In addition, we report on the properties of organic and polymer films deposited by RIR-MAPLE and/or RIR-PLD, such as Alq3 [tris(8-hydroxyquinoline) aluminum] and PEDOT:PSS [poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)]. Finally, the challenges and potential for commercializing RIR-MAPLE/PLD, such as industrial scale-up issues, are discussed.

  12. Silicon opto-electronic wavelength tracker based on an asymmetric 2x3 Mach-Zehnder Interferometer

    OpenAIRE

    Doménech Gómez, José David; Sanchez Fandiño, Javier Antonio; Gargallo Jaquotot, Bernardo Andrés; Baños Lopez, Rocio; Muñoz Muñoz, Pascual

    2014-01-01

    In this paper we report on the experimental demonstration of a Silicon-on-Insulator opto-electronic wavelength tracker for the optical telecommunication C-band. The device consist of a 2x3 Mach-Zehnder Interferometer (MZI) with 10 pm resolution and photo-detectors integrated on the same chip. The MZI is built interconnecting two Multimode Interference (MMI) couplers with two waveguides whose length difference is 56 mm. The first MMI has a coupling ratio of 95:05 to com...

  13. Flexible manufacturing for photonics device assembly

    International Nuclear Information System (INIS)

    Lu, Shin-yee; Young, K.D.

    1994-01-01

    The assembly of photonics devices such as laser diodes, optical modulators, and optoelectronics (OE) multi-chip modules usually requires the placement of micron-size devices, and sub-micron precision attachment between optical fibers and diodes or waveguide modulators (pigtailing). This is a labor-intensive process. Studies done by the OE industry have shown that 95% of the cost of a pigtailed photonic device is attributed to the current practice of manual alignment and bonding techniques. At Lawrence Livermore National Laboratory, the authors are working to reduce the cost of packaging OE devices, through the use of automation

  14. GaAs photovoltaics and optoelectronics using releasable multilayer epitaxial assemblies.

    Science.gov (United States)

    Yoon, Jongseung; Jo, Sungjin; Chun, Ik Su; Jung, Inhwa; Kim, Hoon-Sik; Meitl, Matthew; Menard, Etienne; Li, Xiuling; Coleman, James J; Paik, Ungyu; Rogers, John A

    2010-05-20

    Compound semiconductors like gallium arsenide (GaAs) provide advantages over silicon for many applications, owing to their direct bandgaps and high electron mobilities. Examples range from efficient photovoltaic devices to radio-frequency electronics and most forms of optoelectronics. However, growing large, high quality wafers of these materials, and intimately integrating them on silicon or amorphous substrates (such as glass or plastic) is expensive, which restricts their use. Here we describe materials and fabrication concepts that address many of these challenges, through the use of films of GaAs or AlGaAs grown in thick, multilayer epitaxial assemblies, then separated from each other and distributed on foreign substrates by printing. This method yields large quantities of high quality semiconductor material capable of device integration in large area formats, in a manner that also allows the wafer to be reused for additional growths. We demonstrate some capabilities of this approach with three different applications: GaAs-based metal semiconductor field effect transistors and logic gates on plates of glass, near-infrared imaging devices on wafers of silicon, and photovoltaic modules on sheets of plastic. These results illustrate the implementation of compound semiconductors such as GaAs in applications whose cost structures, formats, area coverages or modes of use are incompatible with conventional growth or integration strategies.

  15. Nuclear physics and optoelectronics presence in industry, medicine and environment

    International Nuclear Information System (INIS)

    Robu, Maria; Peteu, Gh.

    2000-01-01

    This paper reveals applications of Nuclear Physics and Optoelectronics in numerous fields of interest in industry, medicine, environment. In the first part of the work basic elements are analyzed, among which: - the large possibilities offered by the investigation, analysis and testing techniques based on nuclear physics and optoelectronics; - the superior qualitative and quantitative characteristics of these techniques, with varied applicability in fields from industry, medicine and environment. These applications refers to: - elemental analyses of content and impurities; - non-destructive testing with X and gamma radiations; - investigations with radioactive and activable tracers in trophic chains as for instance, ground-vegetation-products-consumers-environment, including also the systemic pollution factors; - complex investigations in the interface tritium-vegetation-environment-humans; - techniques and radiopharmaceutical products for medical investigations; - determinations and automatic control for levels, density, thickness, humidity, surfaces covering; - monitoring by means of remote sensing for the evaluation of the environment, vegetation and pollution factors; - applications and production of laser and UV installations; - connections through optical fibres resistant to radiations; - imaging and medical bioengineering; - advances in X ray, laser and ultrasonic radiology; - monitoring with radiations beams. In the final part, there are presented examples of optoelectronics and nuclear physics applications in fields in industry, medicine and environment, with special stress on their basic characteristics and efficiency. (authors)

  16. Optoelectronics-related competence building in Japanese and Western firms

    Science.gov (United States)

    Miyazaki, Kumiko

    1992-05-01

    In this paper, an analysis is made of how different firms in Japan and the West have developed competence related to optoelectronics on the basis of their previous experience and corporate strategies. The sample consists of a set of seven Japanese and four Western firms in the industrial, consumer electronics and materials sectors. Optoelectronics is divided into subfields including optical communications systems, optical fibers, optoelectronic key components, liquid crystal displays, optical disks, and others. The relative strengths and weaknesses of companies in the various subfields are determined using the INSPEC database, from 1976 to 1989. Parallel data are analyzed using OTAF U.S. patent statistics and the two sets of data are compared. The statistical analysis from the database is summarized for firms in each subfield in the form of an intra-firm technology index (IFTI), a new technique introduced to assess the revealed technology advantage of firms. The quantitative evaluation is complemented by results from intensive interviews with the management and scientists of the firms involved. The findings show that there is a marked variation in the way firms' technological trajectories have evolved giving rise to strength in some and weakness in other subfields for the different companies, which are related to their accumulated core competencies, previous core business activities, organizational, marketing, and competitive factors.

  17. Silicon based light-emitting materials and devices

    International Nuclear Information System (INIS)

    Chen Weide

    1999-01-01

    Silicon based light-emitting materials and devices are the key to optoelectronic integration. Recently, there has been significant progress in materials engineering methods. The author reviews the latest developments in this area including erbium doped silicon, porous silicon, nanocrystalline silicon and Si/SiO 2 superlattice structures. The incorporation of these different materials into devices is described and future device prospects are assessed

  18. Nanostructure of highly aromatic graphene nanosheets -- From optoelectronics to electrochemical energy storage applications

    Science.gov (United States)

    Biswas, Sanjib

    aligned network designed to maximize device performance. Monolayers of large sized graphene nanosheets function as highly electrically conducting current collectors within a mesoporous network of smaller graphene nanosheets for improved rate capability of the electrical double layer capacitor (EDLC) electrode. This nano-architecture produces an electrode with superior performance for high power EDLC applications: a high frequency capacitative response; a nearly rectangular cyclic voltammogram at a scanning rate of 1000 mv/sec; a rapid current response; small equivalent series resistance (ESR); and fast ionic diffusion. Integration of this nanostructured graphene nanosheet architecture with conductive polymers or metal oxide nanostructurcs was also investigated to produce similar multilayered structures for electrochemical energy storage applications. These inexpensive graphene nanosheets coupled with this facile and robust nanostructuring process make both this new material and method highly advantageous for many potential applications ranging from optoelectronics to high power electrochemical energy storage applications.

  19. Optoelectronic properties of CC2TA towards a good TADF material

    Science.gov (United States)

    Mishra, Ashok Kumar

    2018-05-01

    2,4-bis{f3-(9H-carbazol-9-yl)-9H-carbazol-9-yl}-6-phenyl-1,3,5-triazine (CC2TA) is a triazine derivatives in which the acceptor phenyltriazine unit is used as the central skeleton and donor bicarbazole units are bonded to both ends of the skeleton. Molecular orbital calculations exhibit that the HOMO and LUMO are locally allocated chiefly in the bicarbazole and phenyltriazine units, respectively. There are a class of organic molecules and polymers which exhibit semiconductor behavior because of nearly free conjugate π-electrons. Hopping of these electrons in molecules forms different excited singlet and triplet states named as excitons. Some of these organic molecules can be set to emit photons by triplet-singlet excitonic transition via a process called Thermally Activated Delayed Fluorescence (TADF) which is exploited for designing the Organic Light Emitting diode (OLED.) CC2TA is one of these reported noble metal-free TADF molecules which offers unique opto electronic properties arising from the reverse intersystem crossing between the lowest singlet (S) and triplet (T) excited states. Its ability to harvest triplet excitons for fluorescence through facilitated reverse intersystem crossing (T→S) could directly impact their properties and performances, which is attractive for a wide variety of low-cost optoelectronic device. In the present study, the CC2TA compounds have been taken up for the investigation of various optoelectronic properties including the thermally activated delayed fluorescence (TADF) by using the Koopmans Method and Density Functional Theory. The present study discusses the utility of the CC2TA organic semiconductor as a suitable TADF material essential for developing an efficient Organic Light Emitting Diode (OLED).

  20. Light-matter Interactions in Semiconductors and Metals: From Nitride Optoelectronics to Quantum Plasmonics

    Science.gov (United States)

    Narang, Prineha

    This thesis puts forth a theory-directed approach coupled with spectroscopy aimed at the discovery and understanding of light-matter interactions in semiconductors and metals. The first part of the thesis presents the discovery and development of Zn-IV nitride materials. The commercial prominence in the optoelectronics industry of tunable semiconductor alloy materials based on nitride semiconductor devices, specifically InGaN, motivates the search for earth-abundant alternatives for use in efficient, high-quality optoelectronic devices. II-IV-N2 compounds, which are closely related to the wurtzite-structured III-N semiconductors, have similar electronic and optical properties to InGaN namely direct band gaps, high quantum efficiencies and large optical absorption coefficients. The choice of different group II and group IV elements provides chemical diversity that can be exploited to tune the structural and electronic properties through the series of alloys. The first theoretical and experimental investigation of the ZnSnxGe1--xN2 series as a replacement for III-nitrides is discussed here. The second half of the thesis shows ab-initio calculations for surface plasmons and plasmonic hot carrier dynamics. Surface plasmons, electromagnetic modes confined to the surface of a conductor-dielectric interface, have sparked renewed interest because of their quantum nature and their broad range of applications. The decay of surface plasmons is usually a detriment in the field of plasmonics, but the possibility to capture the energy normally lost to heat would open new opportunities in photon sensors, energy conversion devices and switching. A theoretical understanding of plasmon-driven hot carrier generation and relaxation dynamics in the ultrafast regime is presented here. Additionally calculations for plasmon-mediated upconversion as well as an energy-dependent transport model for these non-equilibrium carriers are shown. Finally, this thesis gives an outlook on the

  1. Advanced educational program in optoelectronics for undergraduates and graduates in electronics

    Science.gov (United States)

    Vladescu, Marian; Schiopu, Paul

    2015-02-01

    The optoelectronics education included in electronics curricula at Faculty of Electronics, Telecommunications and Information Technology of "Politehnica" University of Bucharest started in early '90s, and evolved constantly since then, trying to address the growing demand of engineers with a complex optoelectronics profile and to meet the increased requirements of microelectronics, optoelectronics, and lately nanotechnologies. Our goal is to provide a high level of theoretical background combined with advanced experimental tools in laboratories, and also with simulation platforms. That's why we propose an advanced educational program in optoelectronics for both grades of our study program, bachelor and master.

  2. Analysis of optoelectronic strategic planning in Taiwan by artificial intelligence portfolio tool

    Science.gov (United States)

    Chang, Rang-Seng

    1992-05-01

    Taiwan ROC has achieved significant advances in the optoelectronic industry with some Taiwan products ranked high in the world market and technology. Six segmentations of optoelectronic were planned. Each one was divided into several strategic items, design artificial intelligent portfolio tool (AIPT) to analyze the optoelectronic strategic planning in Taiwan. The portfolio is designed to provoke strategic thinking intelligently. This computer- generated strategy should be selected and modified by the individual. Some strategies for the development of the Taiwan optoelectronic industry also are discussed in this paper.

  3. Graduate studies on optoelectronics in Argentina: an experience

    Science.gov (United States)

    Fernández, Juan C.; Garea, María. T.; Isaurralde, Silvia; Perez, Liliana I.; Raffo, Carlos A.

    2014-07-01

    The number of graduate programs in Optoelectronics in Argentina is scarce. The current Optics and Photonics Education Directory lists only three programs. One of them was launched in 2001 in the Facultad de Ingeniería (College of Engineering), Universidad de Buenos Aires (UBA). This was the first graduate program in the field, leading to a Master Degree in Optoelectronics. This decision arose from the demand of telecommunications industries and several estate- or private-funded research institutions working with us in the fields of lasers, optics, remote sensing, etc. A great bonus was the steady work, during several decades, of research groups in the College on the development of different type of lasers and optical non destructive tests and their engineering applications. As happened in many engineering graduate programs in Argentina at that time, few non full-time students could finish their studies, which called for 800 hours of traditional lecture-recitation classes, and the Master Thesis. In recent years Argentine Education authorities downsized the Master programs to 700 hours of blended learning and we redesigned the Graduate Optoelectronic Engineering Program to meet the challenge, dividing it in two successive one year programs, the first aimed at a professional training for almost immediate insertion in the labor market (called Especialización en Ingeniería Optoelectrónica), and the second (called Maestría en Ingeniería Optoelectrónica y Fotónica) aimed at a more academic and research target to comply with the UBA standards for Master degrees. The present work is a presentation of the new program design, which has begun in the current year.

  4. Sol-gel synthesized ZnO for optoelectronics applications: a characterization review

    Science.gov (United States)

    Harun, Kausar; Hussain, Fayaz; Purwanto, Agus; Sahraoui, Bouchta; Zawadzka, Anna; Azmin Mohamad, Ahmad

    2017-12-01

    The rapid growth in green technology has resulted in a marked increase in the incorporation of ZnO in energy and optoelectronic devices. Research involving ZnO is being given renewed attention in the quest to fully exploit its promising properties. The purity and state of defects in the ZnO system are optimized through several modifications to the synthesis conditions and the starting materials. These works have been verified through a series of characterizations. This review covers the essential characterization outcomes of pure ZnO nanoparticles. Emphasis is placed on recent techniques, examples and some issues concerning sol-gel synthesized ZnO nanoparticles. Thermal, phase, structural and morphological observations are combined to ascertain the level of purity of ZnO. The subsequent elemental and optical characterizations are also discussed. This review would be the collective information and suggestions at one place for investigators to focus on the best development of ZnO-based optical and energy devices.

  5. Battery-free, stretchable optoelectronic systems for wireless optical characterization of the skin.

    Science.gov (United States)

    Kim, Jeonghyun; Salvatore, Giovanni A; Araki, Hitoshi; Chiarelli, Antonio M; Xie, Zhaoqian; Banks, Anthony; Sheng, Xing; Liu, Yuhao; Lee, Jung Woo; Jang, Kyung-In; Heo, Seung Yun; Cho, Kyoungyeon; Luo, Hongying; Zimmerman, Benjamin; Kim, Joonhee; Yan, Lingqing; Feng, Xue; Xu, Sheng; Fabiani, Monica; Gratton, Gabriele; Huang, Yonggang; Paik, Ungyu; Rogers, John A

    2016-08-01

    Recent advances in materials, mechanics, and electronic device design are rapidly establishing the foundations for health monitoring technologies that have "skin-like" properties, with options in chronic (weeks) integration with the epidermis. The resulting capabilities in physiological sensing greatly exceed those possible with conventional hard electronic systems, such as those found in wrist-mounted wearables, because of the intimate skin interface. However, most examples of such emerging classes of devices require batteries and/or hard-wired connections to enable operation. The work reported here introduces active optoelectronic systems that function without batteries and in an entirely wireless mode, with examples in thin, stretchable platforms designed for multiwavelength optical characterization of the skin. Magnetic inductive coupling and near-field communication (NFC) schemes deliver power to multicolored light-emitting diodes and extract digital data from integrated photodetectors in ways that are compatible with standard NFC-enabled platforms, such as smartphones and tablet computers. Examples in the monitoring of heart rate and temporal dynamics of arterial blood flow, in quantifying tissue oxygenation and ultraviolet dosimetry, and in performing four-color spectroscopic evaluation of the skin demonstrate the versatility of these concepts. The results have potential relevance in both hospital care and at-home diagnostics.

  6. New pathways in electronics and optoelectronics driven by new physics of nonconventional materials

    International Nuclear Information System (INIS)

    Kantser, Valeriu

    2015-01-01

    Nonconventional materials (NCM) - 2D materials and topological insulators (TI) - have opened a gateway to search new physical phenomena and states of the condensed matter as well as to pave new platform of modern technology. This stems on their unique attributes - non equivalence of electronic and dielectric states to vacuum ones, topological protection (reduced backscattering), spin momentum locking property, magnetoelectric coupling, generations of new quasiparticles like Majorana fermions. Increasing the surface state contribution in proportion to the bulk is critical to investigate the surface states and for future innovative device applications. The way to achieve this is to configure NCM into nanostructures, which at the same time in combination with others materials significantly enlarge the variety of new states and phenomena. This article reviews the recent progress made in NCM and nano heterostructures investigation. The state of art of different new scenario of engineering topologically interface states in the TI heterostructures are revealed, in particular by using polarization fields and antiferromagnetic ordering. Some of new proposals for innovative electronic and optoelectronic devices are discussed. (author)

  7. Integrated Automatic Test System for Airborne Optoelectronic Pods

    International Nuclear Information System (INIS)

    Zhang, Z M; Ding, M J; Wang, L

    2006-01-01

    Based on the introduction of the construction and basic principle of the airborne optoelectronic pod, in accordance with the performance standards of the pod, the total solution scheme of the automatic test system used for testing the combination property is proposed in this paper. The main structure, hardware and software design of the system based on the virtual instruments technology are also discussed in detail. The result of the true run proves the practicality, efficiency, high accuracy and other characteristics of the computer aided testing system based on virtual instruments

  8. SPEKTROP DPU: optoelectronic platform for fast multispectral imaging

    Science.gov (United States)

    Graczyk, Rafal; Sitek, Piotr; Stolarski, Marcin

    2010-09-01

    In recent years it easy to spot and increasing need of high-quality Earth imaging in airborne and space applications. This is due fact that government and local authorities urge for up to date topological data for administrative purposes. On the other hand, interest in environmental sciences, push for ecological approach, efficient agriculture and forests management are also heavily supported by Earth images in various resolutions and spectral ranges. "SPEKTROP DPU: Opto-electronic platform for fast multi-spectral imaging" paper describes architectural datails of data processing unit, part of universal and modular platform that provides high quality imaging functionality in aerospace applications.

  9. Measuring processes with opto-electronic semiconductor components

    International Nuclear Information System (INIS)

    1985-01-01

    This is a report on the state of commercially available semiconductor emitters and detectors for the visible, near, middle and remote infrared range. A survey is given on the distance, speed, flow and length measuring techniques using opto-electronic components. Automatic focussing, the use of light barriers, non-contact temperature measurements, spectroscopic gas, liquid and environmental measurement techniques and gas analysis in medical techniques show further applications of the new components. The modern concept of guided radiation in optical fibres and their use in system technology is briefly explained. (DG) [de

  10. Optoelectronic imaging of speckle using image processing method

    Science.gov (United States)

    Wang, Jinjiang; Wang, Pengfei

    2018-01-01

    A detailed image processing of laser speckle interferometry is proposed as an example for the course of postgraduate student. Several image processing methods were used together for dealing with optoelectronic imaging system, such as the partial differential equations (PDEs) are used to reduce the effect of noise, the thresholding segmentation also based on heat equation with PDEs, the central line is extracted based on image skeleton, and the branch is removed automatically, the phase level is calculated by spline interpolation method, and the fringe phase can be unwrapped. Finally, the imaging processing method was used to automatically measure the bubble in rubber with negative pressure which could be used in the tire detection.

  11. All-optoelectronic continuous wave THz imaging for biomedical applications

    International Nuclear Information System (INIS)

    Siebert, Karsten J; Loeffler, Torsten; Quast, Holger; Thomson, Mark; Bauer, Tobias; Leonhardt, Rainer; Czasch, Stephanie; Roskos, Hartmut G

    2002-01-01

    We present an all-optoelectronic THz imaging system for ex vivo biomedical applications based on photomixing of two continuous-wave laser beams using photoconductive antennas. The application of hyperboloidal lenses is discussed. They allow for f-numbers less than 1/2 permitting better focusing and higher spatial resolution compared to off-axis paraboloidal mirrors whose f-numbers for practical reasons must be larger than 1/2. For a specific histological sample, an analysis of image noise is discussed

  12. Biotunable Nanoplasmonic Filter on Few-Layer MoS2 for Rapid and Highly Sensitive Cytokine Optoelectronic Immunosensing.

    Science.gov (United States)

    Park, Younggeun; Ryu, Byunghoon; Oh, Bo-Ram; Song, Yujing; Liang, Xiaogan; Kurabayashi, Katsuo

    2017-06-27

    Monitoring of the time-varying immune status of a diseased host often requires rapid and sensitive detection of cytokines. Metallic nanoparticle-based localized surface plasmon resonance (LSPR) biosensors hold promise to meet this clinical need by permitting label-free detection of target biomolecules. These biosensors, however, continue to suffer from relatively low sensitivity as compared to conventional immunoassay methods that involve labeling processes. Their response speeds also need to be further improved to enable rapid cytokine quantification for critical care in a timely manner. In this paper, we report an immunobiosensing device integrating a biotunable nanoplasmonic optical filter and a highly sensitive few-layer molybdenum disulfide (MoS 2 ) photoconductive component, which can serve as a generic device platform to meet the need of rapid cytokine detection with high sensitivity. The nanoplasmonic filter consists of anticytokine antibody-conjugated gold nanoparticles on a SiO 2 thin layer that is placed 170 μm above a few-layer MoS 2 photoconductive flake device. The principle of the biosensor operation is based on tuning the delivery of incident light to the few-layer MoS 2 photoconductive flake thorough the nanoplasmonic filter by means of biomolecular surface binding-induced LSPR shifts. The tuning is dependent on cytokine concentration on the nanoplasmonic filter and optoelectronically detected by the few-layer MoS 2 device. Using the developed optoelectronic biosensor, we have demonstrated label-free detection of IL-1β, a pro-inflammatory cytokine, with a detection limit as low as 250 fg/mL (14 fM), a large dynamic range of 10 6 , and a short assay time of 10 min. The presented biosensing approach could be further developed and generalized for point-of-care diagnosis, wearable bio/chemical sensing, and environmental monitoring.

  13. Charge-coupled device area detector for low energy electrons

    Czech Academy of Sciences Publication Activity Database

    Horáček, Miroslav

    2003-01-01

    Roč. 74, č. 7 (2003), s. 3379 - 3384 ISSN 0034-6748 R&D Projects: GA ČR GA102/00/P001 Institutional research plan: CEZ:AV0Z2065902 Keywords : low energy electrons * charged-coupled device * detector Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.343, year: 2003

  14. Near infrared group IV optoelectronics and novel pre-cursors for CVD epitaxy

    Science.gov (United States)

    Hazbun, Ramsey Michael

    Near infrared and mid infrared optoelectronic devices have become increasingly important for the telecommunications, security, and medical imaging industries. The addition of nitrogen to III-V alloys has been widely studied as a method of modifying the band gap for mid infrared (IR) applications. In xGa1-xSb1-y Ny/InAs strained-layer superlattices with type-II (staggered) energy offsets on GaSb substrates, were modeled using eight-band k˙p simulations to analyze the superlattice miniband energies. Three different zero-stress strain balance conditions are reported: fixed superlattice period thickness, fixed InAs well thickness, and fixed InxGa1-xSb 1-yNy barrier thickness. Optoelectronics have traditionally been the realm of III-V semiconductors due to their direct band gap, while integrated circuit chips have been the realm of Group IV semiconductors such as silicon because of its relative abundance and ease of use. Recently the alloying of Sn with Ge and Si has been shown to allow direct band-gap light emission. This presents the exciting prospect of integrating optoelectronics into current Group IV chip fabrication facilities. However, new approaches for low temperature growth are needed to realize these new SiGeSn alloys. Silicon-germanium epitaxy via ultra-high vacuum chemical vapor deposition has the advantage of allowing low process temperatures. Deposition processes are sensitive to substrate surface preparation and the time delay between oxide removal and epitaxial growth. A new monitoring process utilizing doped substrates and defect decoration etching is demonstrated to have controllable and unique sensitivity to interfacial contaminants. Doped substrates were prepared and subjected to various loading conditions prior to the growth of typical Si/SiGe bilayers. The defect densities were correlated to the concentration of interfacial oxygen suggesting this monitoring process may be an effective complement to monitoring via secondary ion mass spectrometry

  15. Optoelectronic fowl adenovirus detection based on local electric field enhancement on graphene quantum dots and gold nanobundle hybrid.

    Science.gov (United States)

    Ahmed, Syed Rahin; Mogus, Jack; Chand, Rohit; Nagy, Eva; Neethirajan, Suresh

    2018-04-30

    An optoelectronic sensor is a rapid diagnostic tool that allows for an accurate, reliable, field-portable, low-cost device for practical applications. In this study, template-free In situ gold nanobundles (Au NBs) were fabricated on an electrode for optoelectronic sensing of fowl adenoviruses (FAdVs). Au NB film was fabricated on carbon electrodes working area using L(+) ascorbic acid, gold chroloauric acid and poly-l-lysine (PLL) through modified layer-by-layer (LbL) method. A scanning electron microscopic (SEM) image of the Au NBs revealed a NB-shaped Au structure with many kinks on its surface, which allow local electric field enhancement through light-matter interaction with graphene quantum dots (GQDs). Here, GQDs were synthesized through an autoclave-assisted method. Characterization experiments revealed blue-emissive, well-dispersed GQDs that were 2-3nm in size with the fluorescence emission peak of GQDs located at 405nm. Both Au NBs and GQDs were conjugated with target FAdVs specific antibodies that bring them close to each other with the addition of target FAdVs through antibody-antigen interaction. At close proximity, light-matter interaction between Au NBs and QDs produces a local electric signal enhancement under Ultraviolet-visible (UV-visible) light irradiation that allows the detection of very low concentrations of target virus even in complex biological media. A proposed optoelectronic sensor showed a linear relationship between the target FAdVs and the electric signal up to 10 Plaque forming unit (PFU)/mL with a limit of detection (LOD) of 8.75 PFU/mL. The proposed sensing strategy was 100 times more sensitive than conventional ELISA method. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Optoelectronic polarimeter controlled by a graphical user interface of Matlab

    International Nuclear Information System (INIS)

    Vilardy, J M; Torres, R; Jimenez, C J

    2017-01-01

    We show the design and implementation of an optical polarimeter using electronic control. The polarimeter has a software with a graphical user interface (GUI) that controls the optoelectronic setup and captures the optical intensity measurement, and finally, this software evaluates the Stokes vector of a state of polarization (SOP) by means of the synchronous detection of optical waves. The proposed optoelectronic polarimeter can determine the Stokes vector of a SOP in a rapid and efficient way. Using the polarimeter proposed in this paper, the students will be able to observe (in an optical bench) and understand the different interactions of the SOP when the optical waves pass through to the linear polarizers and retarder waves plates. The polarimeter prototype could be used as a main tool for the students in order to learn the theory and experimental aspects of the SOP for optical waves via the Stokes vector measurement. The proposed polarimeter controlled by a GUI of Matlab is more attractive and suitable to teach and to learn the polarization of optical waves. (paper)

  17. Bioinspired Transparent Laminated Composite Film for Flexible Green Optoelectronics.

    Science.gov (United States)

    Lee, Daewon; Lim, Young-Woo; Im, Hyeon-Gyun; Jeong, Seonju; Ji, Sangyoon; Kim, Yong Ho; Choi, Gwang-Mun; Park, Jang-Ung; Lee, Jung-Yong; Jin, Jungho; Bae, Byeong-Soo

    2017-07-19

    Herein, we report a new version of a bioinspired chitin nanofiber (ChNF) transparent laminated composite film (HCLaminate) made of siloxane hybrid materials (hybrimers) reinforced with ChNFs, which mimics the nanofiber-matrix structure of hierarchical biocomposites. Our HCLaminate is produced via vacuum bag compressing and subsequent UV-curing of the matrix resin-impregnated ChNF transparent paper (ChNF paper). It is worthwhile to note that this new type of ChNF-based transparent substrate film retains the strengths of the original ChNF paper and compensates for ChNF paper's drawbacks as a flexible transparent substrate. As a result, compared with high-performance synthetic plastic films, such as poly(ethylene terephthalate), poly(ether sulfone), poly(ethylene naphthalate), and polyimide, our HCLaminate is characterized to exhibit extremely smooth surface topography, outstanding optical clarity, high elastic modulus, high dimensional stability, etc. To prove our HCLaminate as a substrate film, we use it to fabricate flexible perovskite solar cells and a touch-screen panel. As far as we know, this work is the first to demonstrate flexible optoelectronics, such as flexible perovskite solar cells and a touch-screen panel, actually fabricated on a composite film made of ChNF. Given its desirable macroscopic properties, we envision our HCLaminate being utilized as a transparent substrate film for flexible green optoelectronics.

  18. Development of an optoelectronic holographic platform for otolaryngology applications

    Science.gov (United States)

    Harrington, Ellery; Dobrev, Ivo; Bapat, Nikhil; Flores, Jorge Mauricio; Furlong, Cosme; Rosowski, John; Cheng, Jeffery Tao; Scarpino, Chris; Ravicz, Michael

    2010-08-01

    In this paper, we present advances on our development of an optoelectronic holographic computing platform with the ability to quantitatively measure full-field-of-view nanometer-scale movements of the tympanic membrane (TM). These measurements can facilitate otologists' ability to study and diagnose hearing disorders in humans. The holographic platform consists of a laser delivery system and an otoscope. The control software, called LaserView, is written in Visual C++ and handles communication and synchronization between hardware components. It provides a user-friendly interface to allow viewing of holographic images with several tools to automate holography-related tasks and facilitate hardware communication. The software uses a series of concurrent threads to acquire images, control the hardware, and display quantitative holographic data at video rates and in two modes of operation: optoelectronic holography and lensless digital holography. The holographic platform has been used to perform experiments on several live and post-mortem specimens, and is to be deployed in a medical research environment with future developments leading to its eventual clinical use.

  19. Study and practice of flipped classroom in optoelectronic technology curriculum

    Science.gov (United States)

    Shi, Jianhua; Lei, Bing; Liu, Wei; Yao, Tianfu; Jiang, Wenjie

    2017-08-01

    "Flipped Classroom" is one of the most popular teaching models, and has been applied in more and more curriculums. It is totally different from the traditional teaching model. In the "Flipped Classroom" model, the students should watch the teaching video afterschool, and in the classroom only the discussion is proceeded to improve the students' comprehension. In this presentation, "Flipped Classroom" was studied and practiced in opto-electronic technology curriculum; its effect was analyzed by comparing it with the traditional teaching model. Based on extensive and deep investigation, the phylogeny, the characters and the important processes of "Flipped Classroom" are studied. The differences between the "Flipped Classroom" and the traditional teaching model are demonstrated. Then "Flipped Classroom" was practiced in opto-electronic technology curriculum. In order to obtain high effectiveness, a lot of teaching resources were prepared, such as the high-quality teaching video, the animations and the virtual experiments, the questions that the students should finish before and discussed in the class, etc. At last, the teaching effect was evaluated through analyzing the result of the examination and the students' surveys.

  20. Optoelectronic switch matrix as a look-up table for residue arithmetic.

    Science.gov (United States)

    Macdonald, R I

    1987-10-01

    The use of optoelectronic matrix switches to perform look-up table functions in residue arithmetic processors is proposed. In this application, switchable detector arrays give the advantage of a greatly reduced requirement for optical sources by comparison with previous optoelectronic residue processors.

  1. Optoelectronic characterisation of an individual ZnO nanowire in contact with a micro-grid template

    International Nuclear Information System (INIS)

    Jiang Wei; Gao Hong; Xu Ling-Ling; Ma Jia-Ning; Zhang E; Wei Ping; Lin Jia-Qi

    2011-01-01

    Optoelectronic characterisation of an individual ZnO nanowire in contact with a micro-grid template has been studied. The low-cost micro-grid template made by photolithography is used to fabricate the ohmic contact metal electrodes. The current increases linearly with the bias, indicating good ohmic contacts between the nanowire and the electrodes. The resistivity of the ZnO nanowire is calculated to be 3.8 Ω·cm. We investigate the photoresponses of an individual ZnO nanowire under different light illumination using light emitting diodes (λ = 505 nm, 460 nm, 375 nm) as excitation sources in atmosphere. When individual ZnO nanowire is exposured to different light irradiation, we find that it is extremely sensitive to UV illumination; the conductance is much larger upon UV illumination than that in the dark at room temperature. This phenomenon may be related to the surface oxygen molecule adsorbtion, which indicates their potential application to the optoelectronic switching device. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  2. Bis(5,7-dimethyl-8-hydroxyquinolinato)beryllium(II) complex as optoelectronic material

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Devender, E-mail: devjakhar@gmail.com; Singh, Kapoor; Bhagwan, Shri; Saini, Raman Kumar; Kadyan, Pratap Singh; Singh, Ishwar

    2016-01-15

    Metal complex bis(5,7-dimethyl-8-hydroxyquinolinato)beryllium(II) as a light emissive material had been synthesized and characterized by various spectral techniques. The beryllium complex had high thermal stability (>250 °C) as well as high glass transition temperature (>115 °C). The prepared metal chelate had a strong photoluminescence (PL) emission at 558 nm (FWHM=72 nm) and electroluminescence (EL) at 561 nm (FWHM=55 nm) with good efficiency. Density functional theoretical calculations have been performed to demonstrate the three-dimensional geometries and the frontier molecular orbital energy levels of this metal complex. Sublimed metal chelate formed thin transparent film and found appropriate material for exploring their opto-electronic applications. OLED device was fabricated using this metal complex by vacuum deposition technique with the device configuration of ITO/TPD(30 nm)/Be-complex(30 nm)/BCP(6 nm)/Alq{sub 3}(28 nm)/LiF(1 nm)/Al(100 nm). The emitted color of the EL device showed Commission Internationale d'Eclairage (CIE) color coordinates as x=0.625, y=0.366 corresponding to greenish yellow color. The maximum luminescence of the fabricated device was reported 1364 Cd/m{sup 2} at 22 V. The maximum current efficiency and power efficiency were 1.75 Cd/A and 0.51 lm/W at 10 V respectively for the fabricated OLED device. - Highlights: • Novel greenish yellow light emitting beryllium complex with 5,7-dimethyl-8-hydroxyquinoline was prepared. • The prepared metal complex were characterized by elemental analysis, infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy ({sup 1}H NMR), thermogravimetric analysis (TGA) as well as differential scanning calorimetry (DSC) techniques. • Electron density distribution and the frontier molecular orbital energy levels of resulting metal complex were computed by density functional theory in the course of DFT/B3LYP/6-31G(d,p) studies. • Sublimed synthesized metal complex of beryllium

  3. Bis(5,7-dimethyl-8-hydroxyquinolinato)beryllium(II) complex as optoelectronic material

    International Nuclear Information System (INIS)

    Singh, Devender; Singh, Kapoor; Bhagwan, Shri; Saini, Raman Kumar; Kadyan, Pratap Singh; Singh, Ishwar

    2016-01-01

    Metal complex bis(5,7-dimethyl-8-hydroxyquinolinato)beryllium(II) as a light emissive material had been synthesized and characterized by various spectral techniques. The beryllium complex had high thermal stability (>250 °C) as well as high glass transition temperature (>115 °C). The prepared metal chelate had a strong photoluminescence (PL) emission at 558 nm (FWHM=72 nm) and electroluminescence (EL) at 561 nm (FWHM=55 nm) with good efficiency. Density functional theoretical calculations have been performed to demonstrate the three-dimensional geometries and the frontier molecular orbital energy levels of this metal complex. Sublimed metal chelate formed thin transparent film and found appropriate material for exploring their opto-electronic applications. OLED device was fabricated using this metal complex by vacuum deposition technique with the device configuration of ITO/TPD(30 nm)/Be-complex(30 nm)/BCP(6 nm)/Alq 3 (28 nm)/LiF(1 nm)/Al(100 nm). The emitted color of the EL device showed Commission Internationale d'Eclairage (CIE) color coordinates as x=0.625, y=0.366 corresponding to greenish yellow color. The maximum luminescence of the fabricated device was reported 1364 Cd/m 2 at 22 V. The maximum current efficiency and power efficiency were 1.75 Cd/A and 0.51 lm/W at 10 V respectively for the fabricated OLED device. - Highlights: • Novel greenish yellow light emitting beryllium complex with 5,7-dimethyl-8-hydroxyquinoline was prepared. • The prepared metal complex were characterized by elemental analysis, infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy ( 1 H NMR), thermogravimetric analysis (TGA) as well as differential scanning calorimetry (DSC) techniques. • Electron density distribution and the frontier molecular orbital energy levels of resulting metal complex were computed by density functional theory in the course of DFT/B3LYP/6-31G(d,p) studies. • Sublimed synthesized metal complex of beryllium gave greenish

  4. Understanding the Slow Transient Optoelectronic Response of Hybrid Organic-Inorganic Halide Perovskites

    Science.gov (United States)

    Jacobs, Daniel Louis

    Hybrid organic-inorganic halide perovskites, particularly methylammonium lead triiodide (MAPbI3), have emerged within the past decade as an exciting class of photovoltaic materials. In less than ten years, MAPbI3-based photovoltaic devices have seen unprecedented performance growth, with photoconversion efficiency increasing from 3% to over 22%, making it competitive with traditional high-efficiency solar cells. Furthermore, the fabrication of MAPbI3 devices utilize low-temperature solution processing, which could facilitate ultra low cost manufacturing. However, MAPbI3 suffers from significant instabilities under working conditions that have limited their applications outside of the laboratory. The instability of the MAPbI3 material can be generalized as a complex, slow transient optoelectronic response (STOR). The mechanism of the generalized STOR is dependent on the native defects of MAPbI3, but detailed understanding of the material defect properties is complicated by the complex ionic bonding of MAPbI3. Furthermore, characterization of the intrinsic material's response is complicated by the diverse approach to material processing and device architecture across laboratories around the world. In order to understand and mitigate the significant problems of MAPbI3 devices, a new approach focused on the material response, rather than the full device response, must be pursued. This dissertation highlights the work to analyze and mitigate the STOR intrinsic to MAPbI3. An experimental platform was developed based on lateral interdigitated electrode (IDE) arrays capable of monitoring the current and photoluminescence response simultaneously. By correlating the dynamics of the current and photoluminescence (PL) responses, both charge trapping and ion migration mechanisms were identified to contribute to the STOR. Next, a novel fabrication technique is introduced that is capable of reliably depositing MAPbI3 thin films with grain sizes at least an order of magnitude

  5. Laser ablation of Au-CuO core-shell nanocomposite in water for optoelectronic devices

    Science.gov (United States)

    Ismail, Raid A.; Abdul-Hamed, Ryam S.

    2017-12-01

    Core-shell gold-copper oxide Au-CuO nanocomposites were synthesized using laser ablation of CuO target in colloidal solution of Au nanoparticles (NPs). The effect of laser fluence on the structural, morphological, electrical, and optical properties of Au-CuO nanocomposites was investigated using x-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscope (SEM), transmission electron microscope (TEM), photoluminescence (PL), Fourier transformed infrared spectroscopy (FTIR), Hall measurement, and UV-vis spectroscopy. X-ray diffraction results confirm the formation of polycrystalline Au-CuO NPs with monoclinic structure. The optical energy gap for CuO was 4 eV and for the Au-CuO core-shell nanocomposites was found to be in the range of 3.4-3.7 eV. SEM and TEM investigations revealed that the structure and morphology of Au-CuO core-shell nanocomposites were strongly depending on the laser fluence. A formation of Au-CuO nanospheres and platelets structures was observed. The photoluminescence data showed an emission of broad visible peaks between 407 and 420 nm. The effect of laser fluence on the dark and illuminated I-V characteristics of Au-CuO/n-Si heterojunction photodetectors was investigated and analyzed. The experimental data demonstrated that the photodetector prepared at optimum laser fluence exhibited photosensitivity of 0.6 AW-1 at 800 nm.

  6. Perovskite single crystals and thin films for optoelectronic devices (Conference Presentation)

    Science.gov (United States)

    Li, Gang; Han, Qifeng; Yang, Yang; Bae, Sang-Hoon; Sun, Pengyu

    2016-09-01

    Hybrid organolead trihalide perovskite (OTP) solar cells have developed as a promising candidate in photovoltaics due to their excellent properties including a direct bandgap, strong absorption coefficient, long carrier lifetime, and high mobility. Most recently, formamidinium (NH2CH=NH2+ or FA) lead iodide (FAPbI3) has attracted significant attention due to several advantages: (1) the larger organic FA cation can replace the MA cation and form a more symmetric crystal structure, (2) the smaller bandgap of FAPbI3 allows for near infrared (NIR) absorption, and (3) FAPbI3 has an elevated decomposition temperature and thus potential to improve stability. Single crystals provide an excellent model system to study the intrinsic electrical and optical properties of these materials due to their high purity, which is particularly important to understand the limits of these materials. In this work, we report the growth of large ( 5 millimeter size) single crystal FAPbI3 using a novel liquid based crystallization method. The single crystal FAPbI3 demonstrated a δ-phase to α-phase transition with a color change from yellow to black when heated to 185°C within approximately two minutes. The crystal structures of the two phases were identified and the PL emission peak of the α-phase FAPbI3 (820 nm) shows clear red-shift compared to the FAPbI3 thin film (805 nm). The FAPbI3 single crystal shows a long carrier lifetime of 484 ns, a high carrier mobility of 4.4 cm2·V-1·s-1, and even more interestingly a conductivity of 1.1 × 10-7(ohm·cm)-1, which is approximately one order of magnitude higher than that of the MAPbI3 single crystal. Finally, high performance photoconductivity type photodetectors were successfully demonstrated using the single crystal FAPbI3.

  7. PECASE: Nanostructure Hybrid Organic/Inorganic Materials for Active Opto-Electronic Devices

    Science.gov (United States)

    2011-01-03

    per square) were cleaned via sequential ultrasonic rinses in detergent solution, deionized water, and acetone and then boiled in isopropanol for 5 min...TPD into the blue QDs due to the increased potential barrier at this junction (see band lineup in inset to Figure 4) or to the reduced tunneling rate

  8. Size effect on organic optoelectronics devices: Example of photovoltaic cell efficiency

    International Nuclear Information System (INIS)

    Pandey, A.K.; Nunzi, J.M.; Ratier, B.; Moliton, A.

    2008-01-01

    Electromagnetic study of organic photovoltaic cells design shows that electrical parameters depend drastically on the active area geometry: we theoretically show that electrical parameters are altered when the cell length becomes greater than one centimeter. Experimental verification is provided with simple molecular heterojunction cells with areas from 0.03 to 0.78 cm 2

  9. Transparent Indium Tin Oxide Electrodes on Muscovite Mica for High-Temperature-Processed Flexible Optoelectronic Devices.

    Science.gov (United States)

    Ke, Shanming; Chen, Chang; Fu, Nianqing; Zhou, Hua; Ye, Mao; Lin, Peng; Yuan, Wenxiang; Zeng, Xierong; Chen, Lang; Huang, Haitao

    2016-10-26

    Sn-doped In 2 O 3 (ITO) electrodes were deposited on transparent and flexible muscovite mica. The use of mica substrate makes a high-temperature annealing process (up to 500 °C) possible. ITO/mica retains its low electric resistivity even after continuous bending of 1000 times on account of the unique layered structure of mica. When used as a transparent flexible heater, ITO/mica shows an extremely fast ramping (solar cells (PSCs) with high efficiency.

  10. Synthesis and characterization thin films of conductive polymer (PANI) for optoelectronic device application

    Science.gov (United States)

    Jarad, Amer N.; Ibrahim, Kamarulazizi; Ahmed, Nasser M.

    2016-07-01

    In this work we report preparation and investigation of structural and optical properties of polyaniline conducting polymer. By using sol-gel in spin coating technique to synthesize thin films of conducting polymer polyaniline (PANI). Conducting polymer polyaniline was synthesized by the chemical oxidative polymerization of aniline monomers. The thin films were characterized by technique: Hall effect, High Resolution X-ray diffraction (HR-XRD), Fourier transform infrared (FTIR) spectroscopy, Field emission scanning electron microscopy (FE-SEM), and UV-vis spectroscopy. Polyaniline conductive polymer exhibit amorphous nature as confirmed by HR-XRD. The presence of characteristic bonds of polyaniline was observed from FTIR spectroscopy technique. Electrical and optical properties revealed that (p-type) conductivity PANI with room temperature, the conductivity was 6.289×10-5 (Ω.cm)-1, with tow of absorption peak at 426,805 nm has been attributed due to quantized size of polyaniline conducting polymer.

  11. Semiconducting Nanocrystals in Mesostructured Thin Films for Optical and Opto-Electronic Device Applications

    National Research Council Canada - National Science Library

    Chmelka, Bradley F

    2007-01-01

    ...) nanocomposite films have been measured and controlled to modify, enhance, and understand their optical and/or semiconducting properties over a hierarchy of dimensions, from molecular to macroscopic...

  12. Synthesis of Nanocrystalline ZnS Thin Films via Spray Pyrolysis for Optoelectronic Devices

    Directory of Open Access Journals (Sweden)

    F. Rahman

    2013-02-01

    Full Text Available ZnS thin films were deposited on the glass substrates at a temperature of 350 °C by a low cost spray pyrolysis technique and annealed at 450 °C and 550 °C in a closed furnace. The as-deposited and annealed films were characterized by Energy Dispersive X-ray, X-ray Diffraction and UV-VIS spectrophotometer and dc conductivity by four probe van der Pauw method. The X-ray diffraction spectra of as-deposited films showed amorphous nature and after annealing at 450 °C and 550 °C the films were found polycrystalline nature with wurtzite hexagonal structure. The optical transmission spectra suggest that the fundamental absorption edge in the films is formed by the direct allowed transition. The optical band gap was decreased from 3.75 to 2.5 eV when the as-deposited films were annealed. The existing results of electrical conductivity and the activation energy reveal the semi-conducting behaviour of the samples.

  13. Synthesis and characterization thin films of conductive polymer (PANI) for optoelectronic device application

    Energy Technology Data Exchange (ETDEWEB)

    Jarad, Amer N., E-mail: amer78malay@yahoo.com.my; Ibrahim, Kamarulazizi, E-mail: kamarul@usm.my; Ahmed, Nasser M., E-mail: nas-tiji@yahoo.com [Nano-optoelectronic Research and Technology Laboratory School of physics, University of Sains Malaysia, 11800 Pulau Pinang (Malaysia)

    2016-07-06

    In this work we report preparation and investigation of structural and optical properties of polyaniline conducting polymer. By using sol-gel in spin coating technique to synthesize thin films of conducting polymer polyaniline (PANI). Conducting polymer polyaniline was synthesized by the chemical oxidative polymerization of aniline monomers. The thin films were characterized by technique: Hall effect, High Resolution X-ray diffraction (HR-XRD), Fourier transform infrared (FTIR) spectroscopy, Field emission scanning electron microscopy (FE-SEM), and UV-vis spectroscopy. Polyaniline conductive polymer exhibit amorphous nature as confirmed by HR-XRD. The presence of characteristic bonds of polyaniline was observed from FTIR spectroscopy technique. Electrical and optical properties revealed that (p-type) conductivity PANI with room temperature, the conductivity was 6.289×10{sup −5} (Ω.cm){sup −1}, with tow of absorption peak at 426,805 nm has been attributed due to quantized size of polyaniline conducting polymer.

  14. Ion beam synthesis of semiconductor nanoparticles for Si based optoelectronic devices

    International Nuclear Information System (INIS)

    Gonzalez-Varona, O.; Perez-Rodriguez, A.; Garrido, B.; Bonafos, C.; Lopez, M.; Morante, J.R.; Montserrat, J.; Rodriguez, R.

    2000-01-01

    Intense white (to the eye) luminescence has been obtained by multiple implantation of Si + and C + ions into thermal SiO 2 and a post-implantation annealing process. This white emission is a consequence of the convolution of three luminescence peaks centred at about 1.45 eV (infrared with a long tail in the red), 2.1 eV (yellow) and 2.8 eV (blue). These emissions have been correlated to the synthesis of nanocrystals of Si and SiC, and the existence of C-rich precipitates. Cross section TEM shows a buried layer with dark contrast, which correlates with the maximum of the C implanted profile, and likely with a high density of C-rich amorphous domains. Besides, two kinds of nanocrystalline precipitates are found, which have been identified as Si and hexagonal 6H-SiC by electron diffraction experiments. To our knowledge, these data provide the first experimental evidence on the ion beam synthesis of nanocrystalline 6H-SiC embedded in SiO 2 . Correlation with previous data gives support to the assignment of the infrared, yellow and blue peaks with the Si, C-rich and SiC precipitate phases and/or its interfaces with SiO 2

  15. Ion beam synthesis of semiconductor nanoparticles for Si based optoelectronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Varona, O.; Perez-Rodriguez, A.; Garrido, B.; Bonafos, C.; Lopez, M.; Morante, J.R.; Montserrat, J.; Rodriguez, R

    2000-03-01

    Intense white (to the eye) luminescence has been obtained by multiple implantation of Si{sup +} and C{sup +} ions into thermal SiO{sub 2} and a post-implantation annealing process. This white emission is a consequence of the convolution of three luminescence peaks centred at about 1.45 eV (infrared with a long tail in the red), 2.1 eV (yellow) and 2.8 eV (blue). These emissions have been correlated to the synthesis of nanocrystals of Si and SiC, and the existence of C-rich precipitates. Cross section TEM shows a buried layer with dark contrast, which correlates with the maximum of the C implanted profile, and likely with a high density of C-rich amorphous domains. Besides, two kinds of nanocrystalline precipitates are found, which have been identified as Si and hexagonal 6H-SiC by electron diffraction experiments. To our knowledge, these data provide the first experimental evidence on the ion beam synthesis of nanocrystalline 6H-SiC embedded in SiO{sub 2}. Correlation with previous data gives support to the assignment of the infrared, yellow and blue peaks with the Si, C-rich and SiC precipitate phases and/or its interfaces with SiO{sub 2}.

  16. Strain and Quantum Dots Manipulation in Nitride Compounds for Opto-electronic Devices

    National Research Council Canada - National Science Library

    Bedair, S. M; El-Masry, N. A

    2008-01-01

    Activities during the project period can be divided into two main areas. The first dealt with quantum structure and optical properties of light sources based on GaInN/AlInGaN quantum well structures...

  17. Modeling and Simulation for Particle Radiation Damage to Electronic and Opto-Electronic Devices

    Science.gov (United States)

    2018-01-25

    reflective optics. The same sized apertures on each sample were used in the measurement to ensure the identical radiant flux for each sample. The result of...blackbody, narrow band filters (centered at 3.4 and 4.5 µm), a current pre-amplifier, and a lock -in amplifier. Measurements were performed using front-side

  18. Optical transceiver ICs based on 3D die-stacking of opto-electronic devices

    NARCIS (Netherlands)

    Duan, P.; Raz, O.; Smalbrugge, B.E.; Plassche, van de K.L.; Dorren, H.J.S.

    2013-01-01

    Wafer scale fabrication of the 3D stacked transceivers is discussed. Uniform open eye patterns at 10 Gb/s/channel of both 3D stacked transmitter and receiver ICs indicates that the interconnection technology is robust.

  19. Simultaneous topographical, electrical and optical microscopy of optoelectronic devices at the nanoscale

    KAUST Repository

    Kumar, Naresh; Zoladek-Lemanczyk, Alina; Guilbert, Anne A. Y.; Su, Weitao; Tuladhar, Sachetan M.; Kirchartz, Thomas; Schroeder, Bob C.; McCulloch, Iain; Nelson, Jenny; Roy, Debdulal; Castro, Fernando A.

    2017-01-01

    resolution by combining plasmonic optical signal enhancement with electrical-mode scanning probe microscopy. We demonstrate that this combined approach offers subsurface sensitivity that can be exploited to provide molecular information with a nanoscale

  20. Optoelectronic investigation of nanodiamond interactions with human blood

    Science.gov (United States)

    Ficek, M.; Wróbel, M. S.; Wasowicz, M.; Jedrzejewska-Szczerska, M.

    2016-03-01

    We present optoelectronic investigation of in vitro interactions of whole human blood with different nanodiamond biomarkers. Plasmo-chemical modifications of detonation nanodiamond particles gives the possibility for controlling their surface for biological applications. Optical investigations reveal the biological activity of nanodiamonds in blood dependent on its surface termination. We compare different types of nanodiamonds: commercial non-modified detonation nanodiamonds, and nanodiamonds modified by MW PACVD method with H2-termination, and chemically modified nanodiamond with O2-termination. The absorption spectra, and optical microscope investigations were conducted. The results indicate haemocompatibility of non-modified detonation nanodiamond as well as modified nanodiamonds, which enables their application for drug delivery, as well as sensing applications.

  1. Design and Radiation Assessment of Optoelectronic Transceiver Circuits for ITER

    CERN Document Server

    Leroux, P; Van Uffelen, M; Steyaert, M

    2008-01-01

    The presented work describes the design and characterization results of different electronic building blocks for a MGy gamma radiation tolerant optoelectronic transceiver aiming at ITER applications. The circuits are implemented using the 70GHz fT SiGe HBT in a 0.35μm BiCMOS technology. A VCSEL driver circuit has been designed and measured up to a TID of 1.6 MGy and up to a bit rate of 622Mbps. No significant degradation is seen in the eye opening of the output signal. On the receiver side, both a 1GHz, 3kΩ transimpedance and a 5GHz Cherry-Hooper amplifier with over 20dB voltage gain have been designed.

  2. Heteroclinic dynamics of coupled semiconductor lasers with optoelectronic feedback.

    Science.gov (United States)

    Shahin, S; Vallini, F; Monifi, F; Rabinovich, M; Fainman, Y

    2016-11-15

    Generalized Lotka-Volterra (GLV) equations are important equations used in various areas of science to describe competitive dynamics among a population of N interacting nodes in a network topology. In this Letter, we introduce a photonic network consisting of three optoelectronically cross-coupled semiconductor lasers to realize a GLV model. In such a network, the interaction of intensity and carrier inversion rates, as well as phases of laser oscillator nodes, result in various dynamics. We study the influence of asymmetric coupling strength and frequency detuning between semiconductor lasers and show that inhibitory asymmetric coupling is required to achieve consecutive amplitude oscillations of the laser nodes. These studies were motivated primarily by the dynamical models used to model brain cognitive activities and their correspondence with dynamics obtained among coupled laser oscillators.

  3. Complete diagnostics of pyroactive structures for smart systems of optoelectronics

    Science.gov (United States)

    Bravina, Svetlana L.; Morozovsky, Nicholas V.

    1998-04-01

    The results of study of pyroelectric phenomena in ferroelectric materials for evidence of the possibility to embody the functions promising for creation of smart systems for optoelectronic applications are presented. Designing such systems requires the development of methods for non- destructive complete diagnostics preferably by developing the self-diagnostic ability inherent in materials with the features of smart/intelligent ones. The complex method of complete non-destructive qualification of pyroactive materials based on the method of dynamic photopyroelectric effect allows the determination of pyroelectric, piezoelectric, ferroelectric, dielectric and thermophysical characteristics. The measuring system which allows the study of these characteristics and also memory effects, switching effects, fatigue and degradation process, self-repair process and others is presented. Sample pyroactive system with increased intelligence, such as systems with built-in adaptive controllable domain structure promising for functional optics are developed and peculiarities of their characterization are discussed.

  4. Microstructure of III-N semiconductors related to their applications in optoelectronics

    Science.gov (United States)

    Leszczynski, M.; Czernetzki, R.; Sarzynski, M.; Krysko, M.; Targowski, G.; Prystawko, P.; Bockowski, M.; Grzegory, I.; Suski, T.; Domagala, J.; Porowski, S.

    2005-03-01

    There has been more than a decade since Shuji Nakamura from Japanese company Nichia constructed the first blue LED based on structure of (AlGaIn)N semiconductor and eight years since he made the first blue laser diode (LD). This work gives a survey on the current technological status with green/blue/violet/UV optoelectronics based on III-N semiconductors in relation with their microstructure. The following devices are presented: i) Low-power green and blue LEDs, ii) High-power LEDs targeting solid-state white lighting, iii) Low-power violet LDs for high definition DVD market, iv) High-power violet LDs, v) UV LEDs. The discussion will be focused on three main technological problems related to the microstructure of (AlGaIn)N layers in emitters based on III-N semiconductors: i) high density of dislocations in epitaxial layers of GaN on foreign substrates (sapphire, SiC, GaAs), ii), presence of strains, iii) atom segregation in ternary and quaternary compounds.

  5. Synthesis and Optoelectronic Applications of Graphene/Transition Metal Dichalcogenides Flat-Pack Assembly

    KAUST Repository

    Li, Henan

    2017-11-16

    Being a representative candidate from the two-dimensional (2D) materials family, graphene has been one of the most intensively researched candidates because of its ultrahigh carrier mobility, quantum Hall effects, excellent mechanical property and high optical transmittance. Unfortunately, the lack of a band gap makes graphene a poor fit for digital electronics, where the current on/off ratio is critical. Huge efforts have been advocated to discover new 2D layered materials with wonderful properties, which complements the needs of 2D electronics. Appropriately designed graphene based hybrid structure could perform better than its counterpart alone. The graphene hybrid structure soon become one of the most exciting frontiers in advanced 2D materials, and many efforts have been made to create artificial heterostructures by assembling of graphene with various layered materials. In this review, we present the recent development in synthesis and applications of graphene based 2D heterostructures. Although 2D transition metal dichalcogenide semiconductors have been demonstrated as strong candidates for next-generation electronics and optoelectronics, by combining advantages of various properties of 2D materials together with graphene, it is highly possible to build entire digital circuits using atomically thin components, and create many novel devices that can be utilized in different areas.

  6. Synthesis and Optoelectronic Applications of Graphene/Transition Metal Dichalcogenides Flat-Pack Assembly

    KAUST Repository

    Li, Henan; Shi, Yumeng; Li, Lain-Jong

    2017-01-01

    Being a representative candidate from the two-dimensional (2D) materials family, graphene has been one of the most intensively researched candidates because of its ultrahigh carrier mobility, quantum Hall effects, excellent mechanical property and high optical transmittance. Unfortunately, the lack of a band gap makes graphene a poor fit for digital electronics, where the current on/off ratio is critical. Huge efforts have been advocated to discover new 2D layered materials with wonderful properties, which complements the needs of 2D electronics. Appropriately designed graphene based hybrid structure could perform better than its counterpart alone. The graphene hybrid structure soon become one of the most exciting frontiers in advanced 2D materials, and many efforts have been made to create artificial heterostructures by assembling of graphene with various layered materials. In this review, we present the recent development in synthesis and applications of graphene based 2D heterostructures. Although 2D transition metal dichalcogenide semiconductors have been demonstrated as strong candidates for next-generation electronics and optoelectronics, by combining advantages of various properties of 2D materials together with graphene, it is highly possible to build entire digital circuits using atomically thin components, and create many novel devices that can be utilized in different areas.

  7. Optoelectronic Properties of Van Der Waals Hybrid Structures: Fullerenes on Graphene Nanoribbons.

    Science.gov (United States)

    Correa, Julián David; Orellana, Pedro Alejandro; Pacheco, Mónica

    2017-03-20

    The search for new optical materials capable of absorbing light in the frequency range from visible to near infrared is of great importance for applications in optoelectronic devices. In this paper, we report a theoretical study of the electronic and optical properties of hybrid structures composed of fullerenes adsorbed on graphene and on graphene nanoribbons. The calculations are performed in the framework of the density functional theory including the van der Waals dispersive interactions. We found that the adsorption of the C 60 fullerenes on a graphene layer does not modify its low energy states, but it has strong consequences for its optical spectrum, introducing new absorption peaks in the visible energy region. The optical absorption of fullerenes and graphene nanoribbon composites shows a strong dependence on photon polarization and geometrical characteristics of the hybrid systems, covering a broad range of energies. We show that an external electric field across the nanoribbon edges can be used to tune different optical transitions coming from nanoribbon-fullerene hybridized states, which yields a very rich electro-absorption spectrum for longitudinally polarized photons. We have carried out a qualitative analysis on the potential of these hybrids as possible donor-acceptor systems in photovoltaic cells.

  8. Optoelectronic Properties of Van Der Waals Hybrid Structures: Fullerenes on Graphene Nanoribbons

    Directory of Open Access Journals (Sweden)

    Julián David Correa

    2017-03-01

    Full Text Available The search for new optical materials capable of absorbing light in the frequency range from visible to near infrared is of great importance for applications in optoelectronic devices. In this paper, we report a theoretical study of the electronic and optical properties of hybrid structures composed of fullerenes adsorbed on graphene and on graphene nanoribbons. The calculations are performed in the framework of the density functional theory including the van der Waals dispersive interactions. We found that the adsorption of the C 60 fullerenes on a graphene layer does not modify its low energy states, but it has strong consequences for its optical spectrum, introducing new absorption peaks in the visible energy region. The optical absorption of fullerenes and graphene nanoribbon composites shows a strong dependence on photon polarization and geometrical characteristics of the hybrid systems, covering a broad range of energies. We show that an external electric field across the nanoribbon edges can be used to tune different optical transitions coming from nanoribbon–fullerene hybridized states, which yields a very rich electro-absorption spectrum for longitudinally polarized photons. We have carried out a qualitative analysis on the potential of these hybrids as possible donor-acceptor systems in photovoltaic cells.

  9. Flexible Near-Field Wireless Optoelectronics as Subdermal Implants for Broad Applications in Optogenetics.

    Science.gov (United States)

    Shin, Gunchul; Gomez, Adrian M; Al-Hasani, Ream; Jeong, Yu Ra; Kim, Jeonghyun; Xie, Zhaoqian; Banks, Anthony; Lee, Seung Min; Han, Sang Youn; Yoo, Chul Jong; Lee, Jong-Lam; Lee, Seung Hee; Kurniawan, Jonas; Tureb, Jacob; Guo, Zhongzhu; Yoon, Jangyeol; Park, Sung-Il; Bang, Sang Yun; Nam, Yoonho; Walicki, Marie C; Samineni, Vijay K; Mickle, Aaron D; Lee, Kunhyuk; Heo, Seung Yun; McCall, Jordan G; Pan, Taisong; Wang, Liang; Feng, Xue; Kim, Tae-Il; Kim, Jong Kyu; Li, Yuhang; Huang, Yonggang; Gereau, Robert W; Ha, Jeong Sook; Bruchas, Michael R; Rogers, John A

    2017-02-08

    In vivo optogenetics provides unique, powerful capabilities in the dissection of neural circuits implicated in neuropsychiatric disorders. Conventional hardware for such studies, however, physically tethers the experimental animal to an external light source, limiting the range of possible experiments. Emerging wireless options offer important capabilities that avoid some of these limitations, but the current size, bulk, weight, and wireless area of coverage is often disadvantageous. Here, we present a simple but powerful setup based on wireless, near-field power transfer and miniaturized, thin, flexible optoelectronic implants, for complete optical control in a variety of behavioral paradigms. The devices combine subdermal magnetic coil antennas connected to microscale, injectable light-emitting diodes (LEDs), with the ability to operate at wavelengths ranging from UV to blue, green-yellow, and red. An external loop antenna allows robust, straightforward application in a multitude of behavioral apparatuses. The result is a readily mass-producible, user-friendly technology with broad potential for optogenetics applications. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Systematic ab initio study of half-Heusler materials for optoelectronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Gruhn, Thomas; Felser, Claudia [Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg University, Mainz (Germany)

    2010-07-01

    The development of new, optimized optoelectronic devices depends crucially on the availability of semiconductors with taylored electronic and structural properties. At the moment, the majority of applications is based on a rather small set of semiconducting materials, while many more semiconductors exist in the huge class of ternary compounds. Especially, the class of 8-electron half-Heusler materials comprises a large number semiconducters with various properties. With the help of ab initio density functional theory we have studied essentially all 8-electron half-Heusler compounds that are of technological relevance. For more than 650 compounds we have determined the optimum configuration by varying the lattice constant and permuting the elements over the sublattices. Within this exceptionally large data set we have studied the band structure and the lattice constants as a function of the electronegativities of the elements, the arrangement of the atoms, and the atomic radii. The results are used to select suitable materials for the buffer layer in thin-film solar cells with a Cu(In,Ga)Se{sub 2} (CIGS) absorber layer. Considering the bandgap and the geometrical matching with the CIGS film, we have obtained a set of 29 compounds that are promissing materials for cadmium-free CIGS buffer layer.

  11. Simple theoretical analysis of the photoemission from quantum confined effective mass superlattices of optoelectronic materials

    Directory of Open Access Journals (Sweden)

    Debashis De

    2011-07-01

    Full Text Available The photoemission from quantum wires and dots of effective mass superlattices of optoelectronic materials was investigated on the basis of newly formulated electron energy spectra, in the presence of external light waves, which controls the transport properties of ultra-small electronic devices under intense radiation. The effect of magnetic quantization on the photoemission from the aforementioned superlattices, together with quantum well superlattices under magnetic quantization, has also been investigated in this regard. It appears, taking HgTe/Hg1−xCdxTe and InxGa1−xAs/InP effective mass superlattices, that the photoemission from these quantized structures is enhanced with increasing photon energy in quantized steps and shows oscillatory dependences with the increasing carrier concentration. In addition, the photoemission decreases with increasing light intensity and wavelength as well as with increasing thickness exhibiting oscillatory spikes. The strong dependence of the photoemission on the light intensity reflects the direct signature of light waves on the carrier energy spectra. The content of this paper finds six different applications in the fields of low dimensional systems in general.

  12. Two-dimensional bismuth nanosheets as prospective photo-detector with tunable optoelectronic performance

    Science.gov (United States)

    Huang, Hao; Ren, Xiaohui; Li, Zhongjun; Wang, Huide; Huang, Zongyu; Qiao, Hui; Tang, Pinghua; Zhao, Jinlai; Liang, Weiyuan; Ge, Yanqi; Liu, Jie; Li, Jianqing; Qi, Xiang; Zhang, Han

    2018-06-01

    Two dimensional Bi nanosheets have been employed to fabricate electrodes for broadband photo-detection. A series of characterization techniques including scanning electron microscopy and high-resolution transmission electron microscopy have verified that Bi nanosheets with intact lamellar structure have been obtained after facile liquid phase exfoliation. In the meanwhile, UV–vis and Raman spectra are also carried out and the inherent optical and physical properties of Bi nanosheets are confirmed. Inherited from the topological characteristics of Bi bulk counterpart, the resultant Bi nanosheet-based photo-detector exhibits preferable photo-response activity as well as environmental robustness. We then evaluate the photo-electrochemical (PEC) performance of the photodetector in 1 M NaOH and 0.5 M Na2SO4 electrolytes, and demonstrated that the as-prepared Bi nanosheets may possess a great potential as PEC-type photo-detector. Additional PEC measurements show that the current density of Bi nanosheets can reach up to 830 nA cm‑2, while an enhanced responsivity (1.8 μA W‑1) had been achieved. We anticipate that this contribution can provide feasibility towards the construction of high-performance elemental Bi nanosheets-based optoelectronic devices in the future.

  13. Flip-chip bonded optoelectronic integration based on ultrathin silicon (UTSi) CMOS

    Science.gov (United States)

    Hong, Sunkwang; Ho, Tawei; Zhang, Liping; Sawchuk, Alexander A.

    2003-06-01

    We describe the design and test of flip-chip bonded optoelectronic CMOS devices based on Peregrine Semiconductor's 0.5 micron Ultra-Thin Silicon on sapphire (UTSi) technology. The UTSi process eliminates the substrate leakage that typically results in crosstalk and reduces parasitic capacitance to the substrate, providing many benefits compared to bulk silicon CMOS. The low-loss synthetic sapphire substrate is optically transparent and has a coefficient of thermal expansion suitable for flip-chip bonding of vertical cavity surface emitting lasers (VCSELs) and detectors. We have designed two different UTSi CMOS chips. One contains a flip-chip bonded 1 x 4 photodiode array, a receiver array, a double edge triggered D-flip flop-based 2047-pattern pseudo random bit stream (PRBS) generator and a quadrature-phase LC-voltage controlled oscillator (VCO). The other chip contains a flip-chip bonded 1 x 4 VCSEL array, a driver array based on high-speed low-voltage differential signals (LVDS) and a full-balanced differential LC-VCO. Each VCSEL driver and receiver has individual input and bias voltage adjustments. Each UTSi chip is mounted on different printed circuit boards (PCBs) which have holes with about 1 mm radius for optical output and input paths through the sapphire substrate. We discuss preliminary testing of these chips.

  14. Organic semiconductor photodiode based on indigo carmine/n-Si for optoelectronic applications

    Science.gov (United States)

    Ganesh, V.; Manthrammel, M. Aslam; Shkir, Mohd.; Yahia, I. S.; Zahran, H. Y.; Yakuphanoglu, F.; AlFaify, S.

    2018-06-01

    The fabrication of indigo carmine/n-Si photodiode has been done, and a robust dark and photocurrent-voltage ( I- V), capacitance vs. voltage ( C-V) and conductance vs. voltage ( G-V) studies were done over a wide range of applied voltage and frequencies. The surface morphology was assessed by atomic force microscope (AFM), and the grain size was measured to be about 66 nm. The reverse current increased with both increasing illumination intensity and bias potential, whereas the forward current increased exponentially with bias potential. The responsivity value was also calculated. Barrier height and ideality factor of diode were estimated through a log (I) vs log (V) plot, and obtained to be 0.843 and 4.75 eV, respectively. The Vbi values are found between 0.95 and 1.2V for frequencies ranging between 100 kHz and 1 MHz. The value of R s is found to be lower at higher frequencies which may be due to a certain distribution of localized interface states. A strong frequency and voltage dependency were observed for interface states density N ss in the present indigo carmine/n-Si photodiode, and this explained the observed capacitance and resistance variation with frequency. These results suggest that the fabricated diode has the potential to be applied in optoelectronic devices.

  15. Structural and Optoelectronic Properties of Cubic CsPbF3 for Novel Applications

    International Nuclear Information System (INIS)

    Murtaza, G.; Ahmad, Iftikhar; Maqbool, M.; Rahnamaye Aliabad, H. A.; Afaq, A.

    2011-01-01

    Chemical bonding as well as structural, electronic and optical properties of CsPbF 3 are calculated using the highly accurate full potential linearized augmented plane-wave method within the framework of density functional theory (DFT). The calculated lattice constant is found to be in good agreement with the experimental results. The electron density plots reveal strong ionic bonding in Cs-F and strong covalent bonding in Pb-F. The calculations show that the material is a direct and wide bandgap semiconductor with a fundamental gap at the R-symmetry point. Optical properties such as the real and imaginary parts of the dielectric function, refractive index, extinction coefficient, reflectivity, optical conductivity and absorption coefficient are also calculated. Based on the calculated wide and direct bandgap, as well as other optical properties of the compound, it is predicted that CsPbF 3 is suitable for optoelectronic devices and anti-reflecting coatings. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  16. Van der Waals epitaxial growth and optoelectronics of large-scale WSe2/SnS2 vertical bilayer p-n junctions.

    Science.gov (United States)

    Yang, Tiefeng; Zheng, Biyuan; Wang, Zhen; Xu, Tao; Pan, Chen; Zou, Juan; Zhang, Xuehong; Qi, Zhaoyang; Liu, Hongjun; Feng, Yexin; Hu, Weida; Miao, Feng; Sun, Litao; Duan, Xiangfeng; Pan, Anlian

    2017-12-04

    High-quality two-dimensional atomic layered p-n heterostructures are essential for high-performance integrated optoelectronics. The studies to date have been largely limited to exfoliated and restacked flakes, and the controlled growth of such heterostructures remains a significant challenge. Here we report the direct van der Waals epitaxial growth of large-scale WSe 2 /SnS 2 vertical bilayer p-n junctions on SiO 2 /Si substrates, with the lateral sizes reaching up to millimeter scale. Multi-electrode field-effect transistors have been integrated on a single heterostructure bilayer. Electrical transport measurements indicate that the field-effect transistors of the junction show an ultra-low off-state leakage current of 10 -14 A and a highest on-off ratio of up to 10 7 . Optoelectronic characterizations show prominent photoresponse, with a fast response time of 500 μs, faster than all the directly grown vertical 2D heterostructures. The direct growth of high-quality van der Waals junctions marks an important step toward high-performance integrated optoelectronic devices and systems.

  17. Molecular beam epitaxy grown Ge/Si pin layer sequence for photonic devices

    International Nuclear Information System (INIS)

    Schulze, J.; Oehme, M.; Werner, J.

    2012-01-01

    A key challenge to obtain a convergence of classical Si-based microelectronics and optoelectronics is the manufacturing of photonic integrated circuits integrable into classical Si-based integrated circuits. This integration would be greatly enhanced if similar facilities and technologies could be used. Therefore one approach is the development of optoelectronic components and devices made from group-IV-based materials such as SiGe, Ge or Ge:Sn. In this paper the optoelectronic performances of a pin diode made from a Ge/Si heterostructure pin layer sequence grown by molecular beam epitaxy are discussed. After a detailed description of the layer sequence growth and the device manufacturing process it will be shown that – depending on the chosen operating point and device design – the diode serves as a broadband high speed photo detector, Franz–Keldysh effect modulator or light emitting diode.

  18. Molecular beam epitaxy grown Ge/Si pin layer sequence for photonic devices

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, J., E-mail: schulze@iht.uni-stuttgart.de; Oehme, M.; Werner, J.

    2012-02-01

    A key challenge to obtain a convergence of classical Si-based microelectronics and optoelectronics is the manufacturing of photonic integrated circuits integrable into classical Si-based integrated circuits. This integration would be greatly enhanced if similar facilities and technologies could be used. Therefore one approach is the development of optoelectronic components and devices made from group-IV-based materials such as SiGe, Ge or Ge:Sn. In this paper the optoelectronic performances of a pin diode made from a Ge/Si heterostructure pin layer sequence grown by molecular beam epitaxy are discussed. After a detailed description of the layer sequence growth and the device manufacturing process it will be shown that - depending on the chosen operating point and device design - the diode serves as a broadband high speed photo detector, Franz-Keldysh effect modulator or light emitting diode.

  19. Device Physics of Narrow Gap Semiconductors

    CERN Document Server

    Chu, Junhao

    2010-01-01

    Narrow gap semiconductors obey the general rules of semiconductor science, but often exhibit extreme features of these rules because of the same properties that produce their narrow gaps. Consequently these materials provide sensitive tests of theory, and the opportunity for the design of innovative devices. Narrow gap semiconductors are the most important materials for the preparation of advanced modern infrared systems. Device Physics of Narrow Gap Semiconductors offers descriptions of the materials science and device physics of these unique materials. Topics covered include impurities and defects, recombination mechanisms, surface and interface properties, and the properties of low dimensional systems for infrared applications. This book will help readers to understand not only the semiconductor physics and materials science, but also how they relate to advanced opto-electronic devices. The last chapter applies the understanding of device physics to photoconductive detectors, photovoltaic infrared detector...

  20. Fiber Bragg grating fabrication for the implementation of sensors in the electronics and optoelectronics laboratory at BUAP

    Science.gov (United States)

    Bracamontes Rodríguez, Y. E.; Beltrán Pérez, G.; Castillo Mixcóatl, J.; Muñoz Aguirre, S.

    2011-09-01

    Fiber Bragg gratings (FBG) are important optical devices since they have been quite successful not only in the field of communications but also in sensor systems and optical fiber lasers. In the sensors area they are generally used as detection elements for different physical parameters such as temperature, strain, flow, etc. In the electronics and optoelectronics laboratory at Benemérita Universidad Autónoma de Puebla (LEyO-BUAP), there are already experimental setups of sensors as well as laser systems, where FBGs are fundamental elements for their adequate performance. However, these FBGs are commercial devices and they present limited characteristics in their transmission profiles, bandwidth and reflectivity. On the other hand, in some occasions, the delivery time from the fabricant to the customer is quite long. Therefore, it is important for LEyO to implement a system to fabricate this kind of devices, which would mean LEyO independence in the technological development. In this work, results of FBGs fabrication based on the phase mask technique are presented. Such mask is optimized for UV and it has a period of 1060 nm. A Nd:YAG pulsed laser with a 5 ns pulse length and an energy of 40 mJ was used as the UV source employing the 4th harmonic generation to obtain a 266 nm wavelength. Ge-doped fiber was used to fabricate the devices.

  1. An Electronic Structure Approach to Charge Transfer and Transport in Molecular Building Blocks for Organic Optoelectronics

    Science.gov (United States)

    Hendrickson, Heidi Phillips

    A fundamental understanding of charge separation in organic materials is necessary for the rational design of optoelectronic devices suited for renewable energy applications and requires a combination of theoretical, computational, and experimental methods. Density functional theory (DFT) and time-dependent (TD)DFT are cost effective ab-initio approaches for calculating fundamental properties of large molecular systems, however conventional DFT methods have been known to fail in accurately characterizing frontier orbital gaps and charge transfer states in molecular systems. In this dissertation, these shortcomings are addressed by implementing an optimally-tuned range-separated hybrid (OT-RSH) functional approach within DFT and TDDFT. The first part of this thesis presents the way in which RSH-DFT addresses the shortcomings in conventional DFT. Environmentally-corrected RSH-DFT frontier orbital energies are shown to correspond to thin film measurements for a set of organic semiconducting molecules. Likewise, the improved RSH-TDDFT description of charge transfer excitations is benchmarked using a model ethene dimer and silsesquioxane molecules. In the second part of this thesis, RSH-DFT is applied to chromophore-functionalized silsesquioxanes, which are currently investigated as candidates for building blocks in optoelectronic applications. RSH-DFT provides insight into the nature of absorptive and emissive states in silsesquioxanes. While absorption primarily involves transitions localized on one chromophore, charge transfer between chromophores and between chromophore and silsesquioxane cage have been identified. The RSH-DFT approach, including a protocol accounting for complex environmental effects on charge transfer energies, was tested and validated against experimental measurements. The third part of this thesis addresses quantum transport through nano-scale junctions. The ability to quantify a molecular junction via spectroscopic methods is crucial to their

  2. Two-step digit-set-restricted modified signed-digit addition-subtraction algorithm and its optoelectronic implementation.

    Science.gov (United States)

    Qian, F; Li, G; Ruan, H; Jing, H; Liu, L

    1999-09-10

    A novel, to our knowledge, two-step digit-set-restricted modified signed-digit (MSD) addition-subtraction algorithm is proposed. With the introduction of the reference digits, the operand words are mapped into an intermediate carry word with all digits restricted to the set {1, 0} and an intermediate sum word with all digits restricted to the set {0, 1}, which can be summed to form the final result without carry generation. The operation can be performed in parallel by use of binary logic. An optical system that utilizes an electron-trapping device is suggested for accomplishing the required binary logic operations. By programming of the illumination of data arrays, any complex logic operations of multiple variables can be realized without additional temporal latency of the intermediate results. This technique has a high space-bandwidth product and signal-to-noise ratio. The main structure can be stacked to construct a compact optoelectronic MSD adder-subtracter.

  3. Optical modeling and simulation of thin-film photovoltaic devices

    CERN Document Server

    Krc, Janez

    2013-01-01

    In wafer-based and thin-film photovoltaic (PV) devices, the management of light is a crucial aspect of optimization since trapping sunlight in active parts of PV devices is essential for efficient energy conversions. Optical modeling and simulation enable efficient analysis and optimization of the optical situation in optoelectronic and PV devices. Optical Modeling and Simulation of Thin-Film Photovoltaic Devices provides readers with a thorough guide to performing optical modeling and simulations of thin-film solar cells and PV modules. It offers insight on examples of existing optical models

  4. AlN/GaN Digital Alloy for Mid- and Deep-Ultraviolet Optoelectronics.

    Science.gov (United States)

    Sun, Wei; Tan, Chee-Keong; Tansu, Nelson

    2017-09-19

    The AlN/GaN digital alloy (DA) is a superlattice-like nanostructure formed by stacking ultra-thin ( ≤ 4 monolayers) AlN barriers and GaN wells periodically. Here we performed a comprehensive study on the electronics and optoelectronics properties of the AlN/GaN DA for mid- and deep-ultraviolet (UV) applications. Our numerical analysis indicates significant miniband engineering in the AlN/GaN DA by tuning the thicknesses of AlN barriers and GaN wells, so that the effective energy gap can be engineered from ~3.97 eV to ~5.24 eV. The band structure calculation also shows that the valence subbands of the AlN/GaN DA is properly rearranged leading to the heavy-hole (HH) miniband being the top valence subband, which results in the desired transverse-electric polarized emission. Furthermore, our study reveals that the electron-hole wavefunction overlaps in the AlN/GaN DA structure can be remarkably enhanced up to 97% showing the great potential of improving the internal quantum efficiency for mid- and deep-UV device application. In addition, the optical absorption properties of the AlN/GaN DA are analyzed with wide spectral coverage and spectral tunability in mid- and deep-UV regime. Our findings suggest the potential of implementing the AlN/GaN DA as a promising active region design for high efficiency mid- and deep-UV device applications.

  5. Progress in the optoelectronic analog signal transfer for high energy particle detectors

    International Nuclear Information System (INIS)

    Tsang, T.; Radeka, V.

    1992-05-01

    We report the progress in the development of a radiation hard Optoelectronic analog system to transfer particle detector signals with high accuracy. We will present the motivation of this study, the operating principle of the optoelectronic system, the system noise study, the recent R ampersand D efforts on radiation effect, temperature stability, and the realization of an integrated l x l6 optical modulator. The issue of photon source for driving such a large-scale optoelectronic modulators is a major concern. We will address this problem by examining different possible photon sources and comment on other possible alternative for signal transfer

  6. A spin-optoelectronic detector for the simultaneous measurement of the degree of circular polarization and intensity of a laser beam

    International Nuclear Information System (INIS)

    Khamari, Shailesh K.; Porwal, S.; Oak, S. M.; Sharma, T. K.

    2015-01-01

    Simultaneous measurement of the degree of circular polarization and intensity of a laser beam is essential in advanced photonic applications. However, it is not feasible with conventional helicity dependent detectors where an additional detector is needed to measure the intensity. Here, we report the development of a spin-optoelectronic detector that can measure the degree of circular polarization and the intensity of a laser beam simultaneously. The principle of operation of device is based on the two independent fundamental phenomena occurring in Au/InP hybrid structures, namely, Inverse Spin Hall Effect (ISHE) and the Photo-Voltaic (PV) Effect. The magnitude of ISHE and PV signals is simultaneously measured across the two pairs of contacts that are made on the top of device. No cross talk is observed between the two detectors made on the same chip. The all-electronic compact device is fast, operates at room temperature, and opens up the possibility of many applications in an integrated optoelectronic platform

  7. Comparing of γ-ray, proton and neutron radiation effects on optoelectronics for space

    International Nuclear Information System (INIS)

    Yu Qingkui; Tang Min; Meng Meng; Li Pengwei; Wen Ping; Li Haian; Tang Jiesen; Wang Sixin; Song Yamei

    2014-01-01

    We performed irradiation test on optoelectronics with γ-rays, proton and neutron. The electrical measurements were performed pre and after irradiation. The degradations induced by each radiation source was compared. (authors)

  8. Temperature-Induced Lattice Relaxation of Perovskite Crystal Enhances Optoelectronic Properties and Solar Cell Performance

    KAUST Repository

    Banavoth, Murali; Yengel, Emre; Peng, Wei; Chen, Zhijie; Alias, Mohd Sharizal; Alarousu, Erkki; Ooi, Boon S.; Burlakov, Victor; Goriely, Alain; Eddaoudi, Mohamed; Bakr, Osman; Mohammed, Omar F.

    2016-01-01

    Hybrid organic-inorganic perovskite crystals have recently become one of the most important classes of photoactive materials in the solar cell and optoelectronic communities. Albeit improvements have focused on state-of-the-art technology including

  9. Research and development of photovoltaic power system. Study of carrier dynamics in a-Si from optical and optoelectronic properties; Taiyoko hatsuden system no kenky kaihatsu. Amorphous silicon no koden tokusei to sono carrier dynamics no kogakuteki kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Hamakawa, K [Osaka University, Osaka (Japan). Faculty of Engineering Science

    1994-12-01

    This paper reports the result obtained during fiscal 1994 on research on an optical study of optoelectronic properties of amorphous silicon and its carrier dynamics. Studies have been performed on elucidation of the optoelectronic conversion mechanism in an a-Si film p-i-n junction system and the relationship of the mechanism with the optoelectronic properties. In the studies, optically induced defect level distribution was evaluated by using the modulated optical current spectroscopy, and confirmation was made on model forecast and qualitative agreement, such as large increase in neutral defect levels in association with beam irradiation. In research on elucidation of a film forming mechanism for a-Si based alloys, and material property control, a high-sensitivity reflective infrared spectroscopy was used to observe mechanisms such as treatments and processes given in device fabrication. In research on optical and optoelectronic properties of an s-Si alloy thin film by using the modulated spectroscopy, a new evaluation technology dealing with amorphous semiconductors was developed. The technology separately evaluates carrier migration factors of electrons and holes by combining polarization angle dependence of electro-absorption signals with hole migration measurements. 4 figs.

  10. Technical quality assessment of an optoelectronic system for movement analysis

    International Nuclear Information System (INIS)

    Sapienza University of Rome (Italy))" data-affiliation=" (Department of Mechanical and Aerospace Engineering, Sapienza University of Rome (Italy))" >Di Marco, R; Sapienza University of Rome (Italy))" data-affiliation=" (Department of Mechanical and Aerospace Engineering, Sapienza University of Rome (Italy))" >Patanè, F; Sapienza University of Rome (Italy))" data-affiliation=" (Department of Mechanical and Aerospace Engineering, Sapienza University of Rome (Italy))" >Cappa, P; Rossi, S

    2015-01-01

    The Optoelectronic Systems (OS) are largely used in gait analysis to evaluate the motor performances of healthy subjects and patients. The accuracy of marker trajectories reconstruction depends on several aspects: the number of cameras, the dimension and position of the calibration volume, and the chosen calibration procedure. In this paper we propose a methodology to evaluate the effects of the mentioned sources of error on the reconstruction of marker trajectories. The novel contribution of the present work consists in the dimension of the tested calibration volumes, which is comparable with the ones normally used in gait analysis; in addition, to simulate trajectories during clinical gait analysis, we provide non-default paths for markers as inputs. Several calibration procedures are implemented and the same trial is processed with each calibration file, also considering different cameras configurations. The RMSEs between the measured trajectories and the optimal ones are calculated for each comparison. To investigate the significant differences between the computed indices, an ANOVA analysis is implemented. The RMSE is sensible to the variations of the considered calibration volume and the camera configurations and it is always inferior to 43 mm

  11. Bismuth Silver Oxysulfide for Photoconversion Applications: Structural and Optoelectronic Properties

    KAUST Repository

    Baqais, Amal Ali Abdulallh; Curutchet, Antton; Ziani, Ahmed; Ait Ahsaine, Hassan; Sautet, Philippe; Takanabe, Kazuhiro; Le Bahers, Tangui

    2017-01-01

    Single-phase bismuth silver oxysulfide, BiAgOS, was prepared by a hydrothermal method. Its structural, morphological and optoelectronic properties were investigated and compared with bismuth copper oxysulfide (BiCuOS). Rietveld refinement of the powder X-ray diffraction (XRD) measurements revealed that the BiAgOS and BiCuOS crystals have the same structure as ZrSiCuAs: the tetragonal space group P4/nmm. X-ray photoelectron spectroscopy (XPS) analyses confirmed that the BiAgOS has a high purity, in contrast with BiCuOS, which tends to have Cu vacancies. The Ag has a monovalent oxidation state, whereas Cu is present in the oxidation states of +1 and +2 in the BiCuOS system. Combined with experimental measurements, density functional theory calculations employing the range-separated hybrid HSE06 exchange-correlation functional with spin-orbit coupling quantitatively elucidated photophysical properties such as ab-sorption coefficients, effective masses and dielectric constants. BiCuOS and BiAgOS were found to have indirect bandgaps of 1.1 and 1.5 eV, respectively. Both possess high dielectric constants and low electron and hole effective masses. Therefore, these materials are expected to have high exciton dissociation capabilities and excellent carrier diffusion properties. This study reveals that BiAgOS is a promising candidate for photoconversion applications.

  12. Bismuth Silver Oxysulfide for Photoconversion Applications: Structural and Optoelectronic Properties

    KAUST Repository

    Baqais, Amal Ali Abdulallh

    2017-09-18

    Single-phase bismuth silver oxysulfide, BiAgOS, was prepared by a hydrothermal method. Its structural, morphological and optoelectronic properties were investigated and compared with bismuth copper oxysulfide (BiCuOS). Rietveld refinement of the powder X-ray diffraction (XRD) measurements revealed that the BiAgOS and BiCuOS crystals have the same structure as ZrSiCuAs: the tetragonal space group P4/nmm. X-ray photoelectron spectroscopy (XPS) analyses confirmed that the BiAgOS has a high purity, in contrast with BiCuOS, which tends to have Cu vacancies. The Ag has a monovalent oxidation state, whereas Cu is present in the oxidation states of +1 and +2 in the BiCuOS system. Combined with experimental measurements, density functional theory calculations employing the range-separated hybrid HSE06 exchange-correlation functional with spin-orbit coupling quantitatively elucidated photophysical properties such as ab-sorption coefficients, effective masses and dielectric constants. BiCuOS and BiAgOS were found to have indirect bandgaps of 1.1 and 1.5 eV, respectively. Both possess high dielectric constants and low electron and hole effective masses. Therefore, these materials are expected to have high exciton dissociation capabilities and excellent carrier diffusion properties. This study reveals that BiAgOS is a promising candidate for photoconversion applications.

  13. Optoelectronic Picosecond Detection of Synchrotron X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Durbin, Stephen M. [Purdue Univ., West Lafayette, IN (United States)

    2017-08-04

    The goal of this research program was to develop a detector that would measure x-ray time profiles with picosecond resolution. This was specifically aimed for use at x-ray synchrotrons, where x-ray pulse profiles have Gaussian time spreads of 50-100 ps (FWHM), so the successful development of such a detector with picosecond resolution would permit x-ray synchrotron studies to break through the pulse width barrier. That is, synchrotron time-resolved studies are currently limited to pump-probe studies that cannot reveal dynamics faster than ~50 ps, whereas the proposed detector would push this into the physically important 1 ps domain. The results of this research effort, described in detail below, are twofold: 1) the original plan to rely on converting electronic signals from a semiconductor sensor into an optical signal proved to be insufficient for generating signals with the necessary time resolution and sensitivity to be widely applicable; and 2) an all-optical method was discovered whereby the x-rays are directly absorbed in an optoelectronic material, lithium tantalate, which can then be probed by laser pulses with the desired picosecond sensitivity for detection of synchrotron x-rays. This research program has also produced new fundamental understanding of the interaction of x-rays and optical lasers in materials that has now created a viable path for true picosecond detection of synchrotron x-rays.

  14. CMOS Optoelectronic Lock-In Amplifier With Integrated Phototransistor Array.

    Science.gov (United States)

    An Hu; Chodavarapu, Vamsy P

    2010-10-01

    We describe the design and development of an optoelectronic lock-in amplifier (LIA) for optical sensing and spectroscopy applications. The prototype amplifier is fabricated using Taiwan Semiconductor Manufacturing Co. complementary metal-oxide semiconductor 0.35-μm technology and uses a phototransistor array (total active area is 400 μm × 640μm) to convert the incident optical signals into electrical currents. The photocurrents are then converted into voltage signals using a transimpedance amplifier for subsequent convenient signal processing by the LIA circuitry. The LIA is optimized to be operational at 20-kHz modulation frequency but is operational in the frequency range from 13 kHz to 25 kHz. The system is tested with a light-emitting diode (LED) as the light source. The noise and signal distortions are suppressed with filters and a phase-locked loop (PLL) implemented in the LIA. The output dc voltage of the LIA is proportional to the incident optical power. The minimum measured dynamic reserve and sensitivity are 1.31 dB and 34 mV/μW, respectively. The output versus input relationship has shown good linearity. The LIA consumes an average power of 12.79 mW with a 3.3-V dc power supply.

  15. Recent Achievements on Photovoltaic Optoelectronic Tweezers Based on Lithium Niobate

    Directory of Open Access Journals (Sweden)

    Angel García-Cabañes

    2018-01-01

    Full Text Available This review presents an up-dated summary of the fundamentals and applications of optoelectronic photovoltaic tweezers for trapping and manipulation of nano-objects on the surface of lithium niobate crystals. It extends the contents of previous reviews to cover new topics and developments which have emerged in recent years and are marking the trends for future research. Regarding the theoretical description of photovoltaic tweezers, detailed simulations of the electrophoretic and dielectrophoretic forces acting on different crystal configurations are discussed in relation to the structure of the obtained trapping patterns. As for the experimental work, we will pay attention to the manipulation and patterning of micro-and nanoparticles that has experimented an outstanding progress and relevant applications have been reported. An additional focus is now laid on recent work about micro-droplets, which is a central topic in microfluidics and optofluidics. New developments in biology and biomedicine also constitute a relevant part of the review. Finally, some topics partially related with photovoltaic tweezers and a discussion on future prospects and challenges are included.

  16. Opto-electronic system for a formal neural network

    Science.gov (United States)

    Heggarty, Keven

    A study on the construction of an optoelectronic system which makes use of the capacities of holographic optics for performing interconnections is presented. In the chosen application (digit recognition) the system acts as an associative memory treating two dimensional data structures (images) in parallel. Starting from the Hopfield model, the synaptic matrix algorithm is modified to adapt the network to optical implementation and improve its discrimination of similar memory vectors. The approach leads to a correlation-reconstruction interpretation of pseudo-inverse techniques. The coding of the computed generated hologram used to perform the connections between two planes which form the outputs and the inputs of the neurons is addressed. This hologram is unusual in that it fulfills simultaneously the necessary correlation and reconstruction functions. The standard techniques of digital holography, usually optimized for one or the other of these functions, is therefore adapted to the specific needs of the connection hologram. In particular, the reduction of the dynamic range of the hologram, whilst retaining the correlation function and a useful degree of shift invariance, is demonstrated. The construction of the prototype system and the adaptation of a laser lithography facility to the fabrication of the holograms are described. The potential of the system is illustrated with experimental results demonstrating its capacity to recognize and discriminate to correlated images from noisy, translated input images. Generalization of the system for use as an interconnection stage in more complicated architectures is illustrated.

  17. Optoelectronic properties of doped hydrothermal ZnO thin films

    KAUST Repository

    Mughal, Asad J.

    2017-03-10

    Group III impurity doped ZnO thin films were deposited on MgAl2O3 substrates using a simple low temperature two-step deposition method involving atomic layer deposition and hydrothermal epitaxy. Films with varying concentrations of either Al, Ga, or In were evaluated for their optoelectronic properties. Inductively coupled plasma atomic emission spectroscopy was used to determine the concentration of dopants within the ZnO films. While Al and Ga-doped films showed linear incorporation rates with the addition of precursors salts in the hydrothermal growth solution, In-doped films were shown to saturate at relatively low concentrations. It was found that Ga-doped films showed the best performance in terms of electrical resistivity and optical absorbance when compared to those doped with In or Al, with a resistivity as low as 1.9 mΩ cm and an optical absorption coefficient of 441 cm−1 at 450 nm.

  18. Radiation-hard Optoelectronics for LHC detector upgrades.

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00375195; Newbold, Dave

    A series of upgrades foreseen for the LHC over the next decade will allow the proton-proton collisions to reach the design center of mass energy of 14 TeV and increase the luminosity to five times (High Luminosity-LHC) the design luminosity by 2027. Radiation-tolerant high-speed optical data transmission links will continue to play an important role in the infrastructure of particle physics experiments over the next decade. A new generation of optoelectronics that meet the increased performance and radiation tolerance limits imposed by the increase in the intensity of the collisions at the interaction points are currently being developed. This thesis focuses on the development of a general purpose bi-directional 5 Gb/s radiation tolerant optical transceiver, the Versatile Transceiver (VTRx), for use by the LHC experiments over the next five years, and on exploring the radiation-tolerance of state-of-the art silicon photonics modulators for HL-LHC data transmission applications. The compliance of the VTRx ...

  19. Influence of TiO2 Nanoparticles on Enhancement of Optoelectronic Properties of PFO-Based Light Emitting Diode

    Directory of Open Access Journals (Sweden)

    Bandar Ali Al-Asbahi

    2013-01-01

    Full Text Available Improvement on optoelectronic properties of poly (9,9′-di-n-octylfluorenyl-2.7-diyl- (PFO- based light emitting diode upon incorporation of TiO2 nanoparticles (NPs is demonstrated. The PFO/TiO2 nanocomposites with different weight ratios between 5 and 35 wt.% were prepared using solution blending method before they were spin coated onto Indium Tin Oxide substrate. Then a thin Al layer was deposited onto the nanocomposite layer to act as top electrode. The nanocomposites were tested as emissive layer in organic light emitting diodes (OLEDs. The TiO2 NPs played the most crucial role in facilitating charge transport and electrical injection and thus improved device performance in terms of turn-on voltage, electroluminescence spectra (EL, luminance, and luminance efficiency. The best composition was OLED with 5 wt.% TiO2 NPs content having moderate surface roughness and well distribution of NPs. The device performance was reduced at higher TiO2 NPs content due to higher surface roughness and agglomeration of TiO2 NPs. This work demonstrated the importance of optimum TiO2 NPs content with uniform distribution and controlled surface roughness of the emissive layer for better device performance.

  20. A multiplexed electronic architecture for opto-electronic patch sensor to effectively monitor heart rate and oxygen saturation

    Science.gov (United States)

    Yan, Liangwen; Hu, Sijung; Alharbi, Samah; Blanos, Panagiotis

    2018-02-01

    To effectively capture human vital signs, a multi-wavelength optoelectronic patch sensor (MOEPS), together with a schematic architecture of electronics, was developed to overcome the drawbacks of present photoplethysmographic (PPG) sensors. To obtain a better performance of in vivo physiological measurement, the optimal illuminations, i.e., light emitting diodes (LEDs) in the MOEPS, whose wavelength is automatically adjusted to each specific subject, were selected to capture better PPG signals. A multiplexed electronic architecture has been well established to properly drive the MOEPS and effectively capture pulsatile waveforms at rest. The protocol was designed to investigate its performance with the participation of 11 healthy subjects aged between 18 and 30. The signals obtained from green (525nm) and orange (595nm) illuminations were used to extract heart rate (HR) and oxygen saturation (SpO2%). These results were compared with data, simultaneously acquired, from a commercial ECG and a pulse oximeter. Considering the difficulty for current devices to attain the SpO2%, a new computing method, to obtain the value of SpO2%, is proposed depended on the green and orange wavelength illuminations. The values of SpO2% between the MOEPS and the commercial Pulse Oximeter devics showed that the results were in good agreement. The values of HR showed close correlation between commercial devices and the MOEPS (HR: r1=0.994(Green); r2=0.992(Orange); r3=0.975(Red); r4=0.990(IR)).

  1. Molecular Orientation of Conjugated Polymer Chains in Nanostructures and Thin Films: Review of Processes and Application to Optoelectronics

    Directory of Open Access Journals (Sweden)

    Varun Vohra

    2017-01-01

    Full Text Available Semiconducting polymers are composed of elongated conjugated polymer backbones and side chains with high solubility and mechanical properties. The combination of these two features results in a high processability and a potential to orient the conjugated backbones in thin films and nanofibers. The thin films and nanofibers are usually composed of highly crystalline (high charge transport and amorphous parts. Orientation of conjugated polymer can result in enhanced charge transport or optical properties as it induces increased crystallinity or preferential orientation of the crystallites. After summarizing the potential strategies to exploit molecular order in conjugated polymer based optoelectronic devices, we will review some of the fabrication processes to induce molecular orientation. In particular, we will review the cases involving molecular and interfacial interactions, unidirectional deposition processes, electrospinning, and postdeposition mechanical treatments. The studies presented here clearly demonstrate that process-controlled molecular orientation of the conjugated polymer chains can result in high device performances (mobilities over 40 cm2·V−1·s−1 and solar cells with efficiencies over 10%. Furthermore, the peculiar interactions between molecularly oriented polymers and polarized light have the potential not only to generate low-cost and low energy consumption polarized light sources but also to fabricate innovative devices such as solar cell integrated LCDs or bipolarized LEDs.

  2. Physical removal of metallic carbon nanotubes from nanotube network devices using a thermal and fluidic process

    International Nuclear Information System (INIS)

    Ford, Alexandra C; Shaughnessy, Michael; Wong, Bryan M; Kane, Alexander A; Krafcik, Karen L; Léonard, François; Kuznetsov, Oleksandr V; Billups, W Edward; Hauge, Robert H

    2013-01-01

    Electronic and optoelectronic devices based on thin films of carbon nanotubes are currently limited by the presence of metallic nanotubes. Here we present a novel approach based on nanotube alkyl functionalization to physically remove the metallic nanotubes from such network devices. The process relies on preferential thermal desorption of the alkyls from the semiconducting nanotubes and the subsequent dissolution and selective removal of the metallic nanotubes in chloroform. The approach is versatile and is applied to devices post-fabrication. (paper)

  3. Amorphous electron-accepting materials for organic optoelectronics

    NARCIS (Netherlands)

    Ganesan, P.

    2007-01-01

    The importance of organic materials for use in electronic devices such as OLEDs, OFETs and photovoltaic cells has increased significantly over the past decade. Organic materials have been attractive candidates for such electronic devices because of their compatibility with high-throughput,

  4. Frugal Droplet Microfluidics Using Consumer Opto-Electronics.

    Science.gov (United States)

    Frot, Caroline; Taccoen, Nicolas; Baroud, Charles N

    2016-01-01

    The maker movement has shown how off-the-shelf devices can be combined to perform operations that, until recently, required expensive specialized equipment. Applying this philosophy to microfluidic devices can play a fundamental role in disseminating these technologies outside specialist labs and into industrial use. Here we show how nanoliter droplets can be manipulated using a commercial DVD writer, interfaced with an Arduino electronic controller. We couple the optical setup with a droplet generation and manipulation device based on the "confinement gradients" approach. This device uses regions of different depths to generate and transport the droplets, which further simplifies the operation and reduces the need for precise flow control. The use of robust consumer electronics, combined with open source hardware, leads to a great reduction in the price of the device, as well as its footprint, without reducing its performance compared with the laboratory setup.

  5. PREFACE: 19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON'19)

    Science.gov (United States)

    González, T.; Martín-Martínez, M. J.; Mateos, J.

    2015-10-01

    The 19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON'19) was held at the Hospedería Fonseca (Universidad de Salamanca, Spain), on 29 June - 2 July, 2015, and was organized by the Electronics Area from the University of Salamanca. The Conference is held biannually and covers the recent progress in the field of electron dynamics in solid-state materials and devices. This was the 19th meeting of the international conference series formerly named Hot Carriers in Semiconductors (HCIS), first held in Modena in 1973. In the edition of 1997 in Berlin the name of the conference changed to International Conference on Nonequilibrium Carrier Dynamics in Semiconductors, keeping the same acronym, HCIS; and finally in the edition of Montpellier in 2009 the name was again changed to the current one, International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON). The latest editions took place in Santa Barbara, USA, in 2011 and Matsue, Japan, in 2013. Research work on electron dynamics involves quite different disciplines, and requires both fundamental and technological scientific efforts. Attendees to the conference come mostly from academic institutions, belonging to both theoretical and experimental groups working in a variety of fields, such as solid-state physics, electronics, optics, electrical engineering, material science, laser physics, etc. In this framework, events like the EDISON conference become a basic channel for the progress in the field. Here, researchers working in different areas can meet, present their latest advances and exchange their ideas. The program of EDISON'19 included 13 invited papers, 61 oral contributions and 73 posters. These contributions originated from scientists in more than 30 different countries. The Conference gathered 140 participants, coming from 24 different countries, most from Europe, but also with a significant participation

  6. Optoelectronic Characterization of Ta-Doped ZnO Thin Films by Pulsed Laser Deposition.

    Science.gov (United States)

    Koo, Horng-Show; Peng, Jo-Chi; Chen, Mi; Chin, Hung-I; Chen, Jaw-Yeh; Wu, Maw-Kuen

    2015-11-01

    Transparent conductive oxide of Ta-doped ZnO (TZO) film with doping amount of 3.0 wt% have been deposited on glass substrates (Corning Eagle XG) at substrate temperatures of 100 to 500 degrees C by the pulsed laser deposition (PLD) technique. The effect of substrate temperature on the structural, optical and electronic characteristics of Ta-doped ZnO (TZO) films with 3.0 wt% dopant of tantalum oxide (Ta2O5) was measured and demonstrated in terms of X-ray diffraction (XRD), ultraviolet-visible spectrometer (UV-Vis), four-probe and Hall-effect measurements. X-ray diffraction pattern shows that TZO films grow in hexagonal crystal structure of wurtzite phase with a preferred orientation of the crystallites along (002) direction and exhibits better physical characteristics of optical transmittance, electrical conductivity, carrier concentration and mobility for the application of window layer in the optoelectronic devices of solar cells, OLEDs and LEDs. The lowest electrical resistivity (ρ) and the highest carrier concentration of the as-deposited film deposited at 300 degrees C are measured as 2.6 x 10(-3) Ω-cm and 3.87 x 10(-20) cm(-3), respectively. The highest optical transmittance of the as-deposited film deposited at 500 degrees C is shown to be 93%, compared with another films deposited below 300 degrees C. It is found that electrical and optical properties of the as-deposited TZO film are greatly dependent on substrate temperature during laser ablation deposition.

  7. Thin film technologies for optoelectronic components in fiber optic communication

    Science.gov (United States)

    Perinati, Agostino

    1998-02-01

    will grow at an annual average rate of 22 percent from 1.3 million fiber-km in 1995 to 3.5 million fiber-km in 2000. The worldwide components market-cable, transceivers and connectors - 6.1 billion in 1994, is forecasted to grow and show a 19 percent combined annual growth rate through the year 2000 when is predicted to reach 17.38 billion. Fiber-in-the-loop and widespread use of switched digital services will dominate this scenario being the fiber the best medium for transmitting multimedia services. As long as communication will partially replace transportation, multimedia services will push forward technology for systems and related components not only for higher performances but for lower cost too in order to get the consumers wanting to buy the new services. In the long distance transmission area (trunk network) higher integration of electronic and optoelectronic functions are required for transmitter and receiver in order to allow for higher system speed, moving from 2.5 Gb/s to 5, 10, 40 Gb/s; narrow band wavelength division multiplexing (WDM) filters are required for higher transmission capacity through multiwavelength technique and for optical amplifier. In the access area (distribution network) passive components as splitters, couplers, filters are needed together with optical amplifiers and transceivers for point-to-multipoint optical signal distribution: main issue in this area is the total cost to be paid by the customer for basic and new services. Multimedia services evolution, through fiber to the home and to the desktop approach, will be mainly affected by the availability of technologies suitable for component consistent integration, high yield manufacturing processes and final low cost. In this paper some of the optoelectronic components and related thin film technologies expected to mainly affect the fiber optic transmission evolution, either for long distance telecommunication systems or for subscriber network, are presented.

  8. Strain-tuned optoelectronic properties of hollow gallium sulphide microspheres

    Science.gov (United States)

    Zhang, Yin; Chen, Chen; Liang, C. Y.; Liu, Z. W.; Li, Y. S.; Che, Renchao

    2015-10-01

    Sulfide semiconductors have attracted considerable attention. The main challenge is to prepare materials with a designable morphology, a controllable band structure and optoelectronic properties. Herein, we report a facile chemical transportation reaction for the synthesis of Ga2S3 microspheres with novel hollow morphologies and partially filled volumes. Even without any extrinsic dopant, photoluminescence (PL) emission wavelength could be facilely tuned from 635 to 665 nm, depending on its intrinsic inhomogeneous strain distribution. Geometric phase analysis (GPA) based on high-resolution transmission electron microscopy (HRTEM) imaging reveals that the strain distribution and the associated PL properties can be accurately controlled by changing the growth temperature gradient, which depends on the distance between the boats used for raw material evaporation and microsphere deposition. The stacking-fault density, lattice distortion degree and strain distribution at the shell interfacial region of the Ga2S3 microspheres could be readily adjusted. Ab initio first-principles calculations confirm that the lowest conductive band (LCB) is dominated by S-3s and Ga-4p states, which shift to the low-energy band as a result of the introduction of tensile strain, well in accordance with the observed PL evolution. Therefore, based on our strain driving strategy, novel guidelines toward the reasonable design of sulfide semiconductors with tunable photoluminescence properties are proposed.Sulfide semiconductors have attracted considerable attention. The main challenge is to prepare materials with a designable morphology, a controllable band structure and optoelectronic properties. Herein, we report a facile chemical transportation reaction for the synthesis of Ga2S3 microspheres with novel hollow morphologies and partially filled volumes. Even without any extrinsic dopant, photoluminescence (PL) emission wavelength could be facilely tuned from 635 to 665 nm, depending on its

  9. Conducting polymers, buckminsterfullerenes, and carbon nanotubes: optoelectronic materials based on architectural diversity of the π-conjugated structure

    International Nuclear Information System (INIS)

    Dai, L.

    2001-01-01

    Recent discovery of superconductivity in self assembled poly(3-hexylthiophene) two-dimensional conjugated sheets indicates the possible applications of plastics even in superconducting optoelectronic devices. Just as the discovery of C 60 has created an entirely new branch of carbon chemistry, the subsequent discovery of carbon nanotubes by lijima in 1991 opened up a new era in material science and nanotechnology. These elongated nanotubes consist of carbon hexagons arranged in a concentric manner with both ends normally capped by fullerene-like structures containing pentagons. Having a conjugated all-carbon structure with unusual molecular symmetries, fullerenes and carbon nanotubes also show interesting electronic, photonic, magnetic and mechanical properties, attractive for various applications, including optical limiters, photovoltaic cells and field emitting displays. For most of the above applications, it is highly desirable to prepare ordered/micropatterned conducting polymers, fullerenes, and carbon nanotubes. Although the microfabrication of conducting polymers has been an active research area for some years, it is a very recent development for fullerenes and carbon nanotubes. Recently, we doped polyaniline (PANI) with a hydrogensulfated fullerenol derivative containing multiple -OSO 3 H groups (i.e. C 60 (OH) 6 (OSO 3 H) 6 ) to produce three-dimensional PANI conductors with a room-temperature conductivity of up to 100 S cm -1 . This value of conductivity is about six orders of magnitude higher than the typical value for C 60 doped conducting polymers. Later, in collaboration with Wan's group at the Chinese Academy of Sciences, we have also synthesized PANI nanotubes via a self assembled C 60 (OH) 6 (OSO 3 H) 6 supramolecular template using (NH 4 ) 2 S 2 O 8 as an oxidant. These results, together with the more recent discovery of a hollow sphere, self assembled by the potassium salt of pentaphenyl fullerene (Ph 5 C 60 K) in water, clearly indicate that

  10. Optoelectronics and defect levels in hydroxyapatite by first-principles

    Science.gov (United States)

    Avakyan, Leon A.; Paramonova, Ekaterina V.; Coutinho, José; Öberg, Sven; Bystrov, Vladimir S.; Bugaev, Lusegen A.

    2018-04-01

    Hydroxyapatite (HAp) is an important component of mammal bones and teeth, being widely used in prosthetic implants. Despite the importance of HAp in medicine, several promising applications involving this material (e.g., in photo-catalysis) depend on how well we understand its fundamental properties. Among the ones that are either unknown or not known accurately, we have the electronic band structure and all that relates to it, including the bandgap width. We employ state-of-the-art methodologies, including density hybrid-functional theory and many-body perturbation theory within the dynamically screened single-particle Green's function approximation, to look at the optoelectronic properties of HAp. These methods are also applied to the calculation of defect levels. We find that the use of a mix of (semi-)local and exact exchange in the exchange-correlation functional brings a drastic improvement to the band structure. Important side effects include improvements in the description of dielectric and optical properties not only involving conduction band (excited) states but also the valence. We find that the highly dispersive conduction band bottom of HAp originates from anti-bonding σ* states along the ⋯OH-OH-⋯ infinite chain, suggesting the formation of a conductive 1D-ice phase. The choice of the exchange-correlation treatment to the calculation of defect levels was also investigated by using the OH-vacancy as a testing model. We find that donor and acceptor transitions obtained within semi-local density functional theory (DFT) differ from those of hybrid-DFT by almost 2 eV. Such a large discrepancy emphasizes the importance of using a high-quality description of the electron-electron interactions in the calculation of electronic and optical transitions of defects in HAp.

  11. Development of optoelectronic monitoring system for ear arterial pressure waveforms

    Science.gov (United States)

    Sasayama, Satoshi; Imachi, Yu; Yagi, Tamotsu; Imachi, Kou; Ono, Toshirou; Man-i, Masando

    1994-02-01

    Invasive intra-arterial blood pressure measurement is the most accurate method but not practical if the subject is in motion. The apparatus developed by Wesseling et al., based on a volume-clamp method of Penaz (Finapres), is able to monitor continuous finger arterial pressure waveforms noninvasively. The limitation of Finapres is the difficulty in measuring the pressure of a subject during work that involves finger or arm action. Because the Finapres detector is attached to subject's finger, the measurements are affected by inertia of blood and hydrostatic effect cause by arm or finger motion. To overcome this problem, the authors made a detector that is attached to subject's ear and developed and optoelectronic monitoring systems for ear arterial pressure waveform (Earpres). An IR LEDs, photodiode, and air cuff comprised the detector. The detector was attached to a subject's ear, and the space adjusted between the air cuff and the rubber plate on which the LED and photodiode were positioned. To evaluate the accuracy of Earpres, the following tests were conducted with participation of 10 healthy male volunteers. The subjects rested for about five minutes, then performed standing and squatting exercises to provide wide ranges of systolic and diastolic arterial pressure. Intra- and inter-individual standard errors were calculated according to the method of van Egmond et al. As a result, average, the averages of intra-individual standard errors for earpres appeared small (3.7 and 2.7 mmHg for systolic and diastolic pressure respectively). The inter-individual standard errors for Earpres were about the same was Finapres for both systolic and diastolic pressure. The results showed the ear monitor was reliable in measuring arterial blood pressure waveforms and might be applicable to various fields such as sports medicine and ergonomics.

  12. Organic bistable light-emitting devices

    Science.gov (United States)

    Ma, Liping; Liu, Jie; Pyo, Seungmoon; Yang, Yang

    2002-01-01

    An organic bistable device, with a unique trilayer structure consisting of organic/metal/organic sandwiched between two outmost metal electrodes, has been invented. [Y. Yang, L. P. Ma, and J. Liu, U.S. Patent Pending, U.S. 01/17206 (2001)]. When the device is biased with voltages beyond a critical value (for example 3 V), the device suddenly switches from a high-impedance state to a low-impedance state, with a difference in injection current of more than 6 orders of magnitude. When the device is switched to the low-impedance state, it remains in that state even when the power is off. (This is called "nonvolatile" phenomenon in memory devices.) The high-impedance state can be recovered by applying a reverse bias; therefore, this bistable device is ideal for memory applications. In order to increase the data read-out rate of this type of memory device, a regular polymer light-emitting diode has been integrated with the organic bistable device, such that it can be read out optically. These features make the organic bistable light-emitting device a promising candidate for several applications, such as digital memories, opto-electronic books, and recordable papers.

  13. Effects of reduction temperature on the optoelectronic properties of diodes based on n-type Si and reduced graphene oxide doped with a conductive polymer

    International Nuclear Information System (INIS)

    Zeng, Jian-Jhou; Lin, Yow-Jon; Ruan, Cheng-He; Lin, Jian-Huang

    2013-01-01

    The effect of reduction temperature on the optoelectronic properties of diodes based on n-type Si and reduced graphene oxide (RGO) doped with a conductive polymer [poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT:PSS)] was examined in this study. It is found that conductivity of RGO-doped PEDOT:PSS films increases with increasing reduction temperature of graphene oxide (GO) sheets. The improvement of electrical conductivity is considered to mainly come from the carrier mobility enhancement. In addition, the ideality factor of n-type Si/RGO-doped PEDOT:PSS diodes decreases with increasing reduction temperature of GO sheets. The device-performance improvement originates from high-mobility hole transport combined with long-lifetime electron trapping in the RGO-doped PEDOT:PSS film. In addition, note that a suitable reduction temperature is an important issue for improving the device performance. (paper)

  14. Beyond Donor-Acceptor (D-A) Approach: Structure-Optoelectronic Properties-Organic Photovoltaic Performance Correlation in New D-A1 -D-A2 Low-Bandgap Conjugated Polymers.

    Science.gov (United States)

    Chochos, Christos L; Drakopoulou, Sofia; Katsouras, Athanasios; Squeo, Benedetta M; Sprau, Christian; Colsmann, Alexander; Gregoriou, Vasilis G; Cando, Alex-Palma; Allard, Sybille; Scherf, Ullrich; Gasparini, Nicola; Kazerouni, Negar; Ameri, Tayebeh; Brabec, Christoph J; Avgeropoulos, Apostolos

    2017-04-01

    Low-bandgap near-infrared polymers are usually synthesized using the common donor-acceptor (D-A) approach. However, recently polymer chemists are introducing more complex chemical concepts for better fine tuning of their optoelectronic properties. Usually these studies are limited to one or two polymer examples in each case study so far, though. In this study, the dependence of optoelectronic and macroscopic (device performance) properties in a series of six new D-A 1 -D-A 2 low bandgap semiconducting polymers is reported for the first time. Correlation between the chemical structure of single-component polymer films and their optoelectronic properties has been achieved in terms of absorption maxima, optical bandgap, ionization potential, and electron affinity. Preliminary organic photovoltaic results based on blends of the D-A 1 -D-A 2 polymers as the electron donor mixed with the fullerene derivative [6,6]-phenyl-C 71 -butyric acid methyl ester demonstrate power conversion efficiencies close to 4% with short-circuit current densities (J sc ) of around 11 mA cm -2 , high fill factors up to 0.70, and high open-circuit voltages (V oc s) of 0.70 V. All the devices are fabricated in an inverted architecture with the photoactive layer processed in air with doctor blade technique, showing the compatibility with roll-to-roll large-scale manufacturing processes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Computational design of surfaces, nanostructures and optoelectronic materials

    Science.gov (United States)

    Choudhary, Kamal

    Properties of engineering materials are generally influenced by defects such as point defects (vacancies, interstitials, substitutional defects), line defects (dislocations), planar defects (grain boundaries, free surfaces/nanostructures, interfaces, stacking faults) and volume defects (voids). Classical physics based molecular dynamics and quantum physics based density functional theory can be useful in designing materials with controlled defect properties. In this thesis, empirical potential based molecular dynamics was used to study the surface modification of polymers due to energetic polyatomic ion, thermodynamics and mechanics of metal-ceramic interfaces and nanostructures, while density functional theory was used to screen substituents in optoelectronic materials. Firstly, polyatomic ion-beams were deposited on polymer surfaces and the resulting chemical modifications of the surface were examined. In particular, S, SC and SH were deposited on amorphous polystyrene (PS), and C2H, CH3, and C3H5 were deposited on amorphous poly (methyl methacrylate) (PMMA) using molecular dynamics simulations with classical reactive empirical many-body (REBO) potentials. The objective of this work was to elucidate the mechanisms by which the polymer surface modification took place. The results of the work could be used in tailoring the incident energy and/or constituents of ion beam for obtaining a particular chemistry inside the polymer surface. Secondly, a new Al-O-N empirical potential was developed within the charge optimized many body (COMB) formalism. This potential was then used to examine the thermodynamic stability of interfaces and mechanical properties of nanostructures composed of aluminum, its oxide and its nitride. The potentials were tested for these materials based on surface energies, defect energies, bulk phase stability, the mechanical properties of the most stable bulk phase, its phonon properties as well as with a genetic algorithm based evolution theory of

  16. MOVPE growth and characterisation of ZnO properties for optoelectronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Oleynik, N.

    2007-03-07

    In this work a new Metalorganic Vapor Phase Epitaxy (MOVPE) method was developed for the growth and doping of high-quality ZnO films. ZnO is a unique optoelectronic material for the effective light generation in the green to the UV spectral range. Optoelectronic applications of ZnO require impurity-free monocrystalline films with smooth surfaces and low concentration of the defects in the crystal lattice. At the beginning of this work only few reports on MOVPE growth of polycrystalline ZnO existed. The low quality of ZnO is attributed to the lack of an epitaxially matched substrate, and gas-phase prereactions between the Zn- and O-precursors. To achieve control over the ZnO quality, several O-precursors were tested for the growth on GaN/Si(111) or GaN/Sapphire substrates at different reactor temperatures and pressures. ZnO layers with XRD rocking curve FWHMs of the (0002) reflection of 180'' and narrow cathodoluminescence of 1.3 meV of the dominant I{sub 8} emission were synthesized using a two-step growth procedure. In this procedure, ZnO is homoepitaxially grown at high temperature using N{sub 2}O as O-precursor on a low temperature grown ZnO buffer layer using tertiary-butanol as O-precursor. p-Type doping of ZnO, which usually exhibits n-type behaviour, is very difficult. This doping asymmetry represents an issue for ZnO-based devices. Beginning from 1992, a growing number of reports have been claiming a fabrication of p-type ZnO, but, due to the missing reproducibilty, they are still questionable. Native defects, non-stoichiometry, and hydrogen are sources of n-type conductivity of ZnO. Together with a low solubility of the potential p-type dopants and deep position of impurity levels, these factors partly explain p-type doping difficulties in ZnO. However, there is no fully described mechanism of the ZnO doping asymmetry yet. In this work, NH{sub 3}, unsymmetrical dimethylhydrazine (UDMHy), diisobutylamine, and NO nitrogen precursors were studied

  17. Modulating the Optoelectronic Properties of Silver Nanowires Films: Effect of Capping Agent and Deposition Technique.

    Science.gov (United States)

    Lopez-Diaz, D; Merino, C; Velázquez, M M

    2015-11-11

    Silver nanowires 90 nm in diameter and 9 µm in length have been synthesized using different capping agents: polyvinyl pyrrolidone (PVP) and alkyl thiol of different chain lengths. The nanowire structure is not influenced by the displacement of PVP by alkyl thiols, although alkyl thiols modify the lateral aggregation of nanowires. We examined the effect of the capping agent and the deposition method on the optical and electrical properties of films prepared by Spray and the Langmuir-Schaefer methodologies. Our results revealed that nanowires capped with PVP and C8-thiol present the best optoelectronic properties. By using different deposition techniques and by modifying the nanowire surface density, we can modulate the optoelectronic properties of films. This strategy allows obtaining films with the optoelectronic properties required to manufacture touch screens and electromagnetic shielding.

  18. Demonstration of an optoelectronic interconnect architecture for a parallel modified signed-digit adder and subtracter

    Science.gov (United States)

    Sun, Degui; Wang, Na-Xin; He, Li-Ming; Weng, Zhao-Heng; Wang, Daheng; Chen, Ray T.

    1996-06-01

    A space-position-logic-encoding scheme is proposed and demonstrated. This encoding scheme not only makes the best use of the convenience of binary logic operation, but is also suitable for the trinary property of modified signed- digit (MSD) numbers. Based on the space-position-logic-encoding scheme, a fully parallel modified signed-digit adder and subtractor is built using optoelectronic switch technologies in conjunction with fiber-multistage 3D optoelectronic interconnects. Thus an effective combination of a parallel algorithm and a parallel architecture is implemented. In addition, the performance of the optoelectronic switches used in this system is experimentally studied and verified. Both the 3-bit experimental model and the experimental results of a parallel addition and a parallel subtraction are provided and discussed. Finally, the speed ratio between the MSD adder and binary adders is discussed and the advantage of the MSD in operating speed is demonstrated.

  19. Estimation of Dynamic Errors in Laser Optoelectronic Dimension Gauges for Geometric Measurement of Details

    Directory of Open Access Journals (Sweden)

    Khasanov Zimfir

    2018-01-01

    Full Text Available The article reviews the capabilities and particularities of the approach to the improvement of metrological characteristics of fiber-optic pressure sensors (FOPS based on estimation estimation of dynamic errors in laser optoelectronic dimension gauges for geometric measurement of details. It is shown that the proposed criteria render new methods for conjugation of optoelectronic converters in the dimension gauge for geometric measurements in order to reduce the speed and volume requirements for the Random Access Memory (RAM of the video controller which process the signal. It is found that the lower relative error, the higher the interrogetion speed of the CCD array. It is shown that thus, the maximum achievable dynamic accuracy characteristics of the optoelectronic gauge are determined by the following conditions: the parameter stability of the electronic circuits in the CCD array and the microprocessor calculator; linearity of characteristics; error dynamics and noise in all electronic circuits of the CCD array and microprocessor calculator.

  20. Modulating the Optoelectronic Properties of Silver Nanowires Films: Effect of Capping Agent and Deposition Technique

    Directory of Open Access Journals (Sweden)

    D. Lopez-Diaz

    2015-11-01

    Full Text Available Silver nanowires 90 nm in diameter and 9 µm in length have been synthesized using different capping agents: polyvinyl pyrrolidone (PVP and alkyl thiol of different chain lengths. The nanowire structure is not influenced by the displacement of PVP by alkyl thiols, although alkyl thiols modify the lateral aggregation of nanowires. We examined the effect of the capping agent and the deposition method on the optical and electrical properties of films prepared by Spray and the Langmuir-Schaefer methodologies. Our results revealed that nanowires capped with PVP and C8-thiol present the best optoelectronic properties. By using different deposition techniques and by modifying the nanowire surface density, we can modulate the optoelectronic properties of films. This strategy allows obtaining films with the optoelectronic properties required to manufacture touch screens and electromagnetic shielding.

  1. Standard cell-based implementation of a digital optoelectronic neural-network hardware.

    Science.gov (United States)

    Maier, K D; Beckstein, C; Blickhan, R; Erhard, W

    2001-03-10

    A standard cell-based implementation of a digital optoelectronic neural-network architecture is presented. The overall structure of the multilayer perceptron network that was used, the optoelectronic interconnection system between the layers, and all components required in each layer are defined. The design process from VHDL-based modeling from synthesis and partly automatic placing and routing to the final editing of one layer of the circuit of the multilayer perceptrons are described. A suitable approach for the standard cell-based design of optoelectronic systems is presented, and shortcomings of the design tool that was used are pointed out. The layout for the microelectronic circuit of one layer in a multilayer perceptron neural network with a performance potential 1 magnitude higher than neural networks that are purely electronic based has been successfully designed.

  2. Optoelectronics in TESLA, LHC and pi-of-the-sky experiments

    CERN Document Server

    Romaniuk, Ryszard; Simrock, Stefan; Wrochna, Grzegorz

    2004-01-01

    Optical and optoelectronics technologies are more and more widely used in the biggest world experiments of high energy and nuclear physics, as well as in the astronomy. The paper is a kind of a broad digest describing the usage of optoelectronics is such experiments and information about some of the involved teams. The described experiments include: TESLA linear accelerator and FEL, Compact Muon Solenoid at LHC and recently started pi-of-the-sky global gamma ray bursts (with associated optical flashes) observation experiment. Optoelectronics and photonics offer several key features which are either extending the technical parameters of existing solutions or adding quite new practical application possibilities. Some of these favorable features of photonic systems are: high selectivity of optical sensors, immunity to some kinds of noise processes, extremely broad bandwidth exchangeable for either terabit rate transmission or ultrashort pulse generation, parallel image processing capability, etc. The following g...

  3. Photovoltaic device

    Energy Technology Data Exchange (ETDEWEB)

    Reese, Jason A; Keenihan, James R; Gaston, Ryan S; Kauffmann, Keith L; Langmaid, Joseph A; Lopez, Leonardo; Maak, Kevin D; Mills, Michael E; Ramesh, Narayan; Teli, Samar R

    2017-03-21

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  4. Photovoltaic device

    Science.gov (United States)

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-06-02

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  5. Photovoltaic device

    Science.gov (United States)

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-09-01

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device (10) with a multilayered photovoltaic cell assembly (100) and a body portion (200) joined at an interface region (410) and including an intermediate layer (500), at least one interconnecting structural member (1500), relieving feature (2500), unique component geometry, or any combination thereof.

  6. Improving the security of optoelectronic delayed feedback system by parameter modulation and system coupling

    Science.gov (United States)

    Liu, Lingfeng; Miao, Suoxia; Cheng, Mengfan; Gao, Xiaojing

    2016-02-01

    A coupled system with varying parameters is proposed to improve the security of optoelectronic delayed feedback system. This system is coupled by two parameter-varied optoelectronic delayed feedback systems with chaotic modulation. Dynamics performance results show that this system has a higher complexity compared to the original one. Furthermore, this system can conceal the time delay effectively against the autocorrelation function and delayed mutual information method and can increase the dimension space of secure parameters to resist brute-force attack by introducing the digital chaotic systems.

  7. Design of optoelectronic system to meter of electrical current to the habitation house

    International Nuclear Information System (INIS)

    Camas, J.; Flores, M.; Anzuelo, G.; Garcia, C.; Juarez, N.; Torres, W.; Mota, R.

    2009-01-01

    In this work, we present an optoelectronic digital meter of electrical current. The development of this design is described step by step with diagram to blocks. The advantage over conventional meters of CFE (Comision Federal de electricidad) and the design proposed are analyzed. Information in the optoelectronic design is controlled by Microcontroller PIC16F877. This Microcontroller uses an external crystal as an oscillator with a 4 MHz frequency. The information is shown in a LCD (Liquid Crystal Display). In addition, to quantify the electrical current was necessary an interruption of light. (Author)

  8. Commercialization issues and funding opportunities for high-performance optoelectronic computing modules

    Science.gov (United States)

    Hessenbruch, John M.; Guilfoyle, Peter S.

    1997-01-01

    Low power, optoelectronic integrated circuits are being developed for high speed switching and data processing applications. These high performance optoelectronic computing modules consist of three primary components: vertical cavity surface emitting lasers, diffractive optical interconnect elements, and detector/amplifier/laser driver arrays. Following the design and fabrication of an HPOC module prototype, selected commercial funding sources will be evaluated to support a product development stage. These include the formation of a strategic alliance with one or more microprocessor or telecommunications vendors, and/or equity investment from one or more venture capital firms.

  9. Piezophototronic Effect in Single-Atomic-Layer MoS 2 for Strain-Gated Flexible Optoelectronics

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wenzhuo [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta GA 30332-0245 USA; Wang, Lei [Department of Electrical Engineering, Columbia University, New York NY 10027 USA; Yu, Ruomeng [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta GA 30332-0245 USA; Liu, Yuanyue [National Renewable Energy Laboratory (NREL), Golden CO 80401 USA; Wei, Su-Huai [National Renewable Energy Laboratory (NREL), Golden CO 80401 USA; Hone, James [Department of Mechanical Engineering, Columbia University, New York NY 10027 USA; Wang, Zhong Lin [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta GA 30332-0245 USA; Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, 100083 Beijing China

    2016-08-03

    Strain-gated flexible optoelectronics are reported based on monolayer MoS2. Utilizing the piezoelectric polarization created at metal-MoS2 interface to modulate the separation/transport of photogenerated carriers, the piezophototronic effect is applied to implement atomic-layer-thick phototransistor. Coupling between piezoelectricity and photogenerated carriers may enable the development of novel optoelectronics.

  10. Effect of Varying Pnictogen Elements (Pn=N, P, As, Sb, Bi) on the Optoelectronic Properties of SrZn2Pn2

    Science.gov (United States)

    Murtaza, G.; Yousaf, N.; Laref, A.; Yaseen, M.

    2018-03-01

    Pnictogen-based Zintl compounds have fascinating properties. Nowadays these compounds have gained exceptional interest in thermoelectric and optoelectronic fields. Therefore, in this work the structural, electronic and optical properties of SrZn2Pn2 (Pn=N, P, As, Sb, Bi) compounds were studied using state-of-the-art density functional theory. The optimised lattice parameters (ɑ, c, c/ɑ and bond lengths) are consistent with the experimental results. The bulk moduli and c/a showed a decrease when changing the Pnictogen (Pn) anion from N to Bi in SrZn2Pn2 (Pn=N, P, As, Sb, Bi). The modified Becke-Johnson potential is used for band structure calculations. All compounds show semiconducting behaviour except SrZn2Bi2, which is metallic. Pn-p, Zn-d and Sr-d play an important role in defining the electronic structure of the compounds. The optical conductivity and absorption coefficient strength are high in visible and ultraviolet regions. These band structures and optical properties clearly show that SrZn2Pn2 compounds are potential candidates in the fields of optoelectronic and photonic devices.

  11. Designing a porous-crystalline structure of β-Ga2O3: a potential approach to tune its opto-electronic properties.

    Science.gov (United States)

    Banerjee, Swastika; Jiang, Xiangwei; Wang, Lin-Wang

    2018-04-04

    β-Ga2O3 has drawn recent attention as a state-of-the-art electronic material due to its stability, optical transparency and appealing performance in power devices. However, it has also found a wider range of opto-electronic applications including photocatalysis, especially in its porous form. For such applications, a lower band gap must be obtained and an electron-hole spatial separation would be beneficial. Like many other metal oxides (e.g. Al2O3), Ga2O3 can also form various types of porous structure. In the present study, we investigate how its optical and electronic properties can be changed in a particular porous structure with stoichiometrically balanced and extended vacancy channels. We apply a set of first principles computational methods to investigate the formation and the structural, dynamic, and opto-electronic properties. We find that such an extended vacancy channel is mechanically stable and has relatively low formation energy. We also find that this results in a spatial separation of the electron and hole, forming a long-lived charge transfer state that has desirable characteristics for a photocatalyst. In addition, the electronic band gap reduces to the vis-region unlike the transparency in the pure β-Ga2O3 crystal. Thus, our systematic study is promising for the application of such a porous structure of β-Ga2O3 as a versatile electronic material.

  12. Optoelectronic properties of XIn2S4 (X = Cd, Mg) thiospinels through highly accurate all-electron FP-LAPW method coupled with modified approximations

    International Nuclear Information System (INIS)

    Yousaf, Masood; Dalhatu, S.A.; Murtaza, G.; Khenata, R.; Sajjad, M.; Musa, A.; Rahnamaye Aliabad, H.A.; Saeed, M.A.

    2015-01-01

    Highlights: • Highly accurate all-electron FP-LAPW+lo method is used. • New physical parameters are reported, important for the fabrication of optoelectronic devices. • A comparative study that involves FP-LAPW+lo method and modified approximations. • Computed band gap values have good agreement with the experimental values. • Optoelectronic results of fundamental importance can be utilized for the fabrication of devices. - Abstract: We report the structural, electronic and optical properties of the thiospinels XIn 2 S 4 (X = Cd, Mg), using highly accurate all-electron full potential linearized augmented plane wave plus local orbital method. In order to calculate the exchange and correlation energies, the method is coupled with modified techniques such as GGA+U and mBJ-GGA, which yield improved results as compared to the previous studies. GGA+SOC approximation is also used for the first time on these compounds to examine the spin orbit coupling effect on the band structure. From the analysis of the structural parameters, robust character is predicted for both materials. Energy band structures profiles are fairly the same for GGA, GGA+SOC, GGA+U and mBJ-GGA, confirming the indirect and direct band gap nature of CdIn 2 S 4 and MgIn 2 S 4 materials, respectively. We report the trend of band gap results as: (mBJ-GGA) > (GGA+U) > (GGA) > (GGA+SOC). Localized regions appearing in the valence bands for CdIn 2 S 4 tend to split up nearly by ≈1 eV in the case of GGA+SOC. Many new physical parameters are reported that can be important for the fabrication of optoelectronic devices. Optical spectra namely, dielectric function (DF), refractive index n(ω), extinction coefficient k(ω), reflectivity R(ω), optical conductivity σ(ω), absorption coefficient α(ω) and electron loss function are discussed. Optical’s absorption edge is noted to be 1.401 and 1.782 for CdIn 2 S 4 and MgIn 2 S 4 , respectively. The prominent peaks in the electron energy spectrum

  13. THE METHOD OF GEOMETRIC CALIBRATION OF OPTOELECTRONIC SYSTEMS BASED ON ELECTRONIC TEST OBJECT

    Directory of Open Access Journals (Sweden)

    D. A. Kozhevnikov

    2017-01-01

    Full Text Available Designing remote sensing of the Earth devices is requires a lot of attention to evaluation lens distortion level and providing the required accuracy values of geometric calibration of optoelectronic systems at all. Test- objects known as most common tools for optical systems geometric calibration. The purpose of the research was creating an automatically method of distortion correction coefficients calculating with a 3 μm precision in the measurement process. The method of geometric calibration of the internal orientation elements of the optical system based on the electronic test object is proposed. The calculation of the test string brightness image from its multispectral image and filtered signal extrema position determination are presented. Ratio of magnitude of the distortion and interval center is given. Three variants of electronic test-objects with different step and element size are considered. Оptimal size of calibration element was defined as 3×3 pixels due to shape of the subpixels with the aspect ratio of the radiating areas about 1 : 3. It is advisable to use IPS as an electronic test object template. An experimental test and measurement stand functional diagram based on the collimator and optical bench «OSK-2CL» is showed. It was determined that test objects with a grid spacing of 4 and 8 pixels can’t provide tolerable image because of non-collimated emission of active sites and scattering on optical surfaces – the shape of the elements is substantially disrupted. Test-object with a 12 pixels grid spacing was used to distortion level analyzing as most suitable.Ratio of coordinate increment and element number graphs for two photographic lenses (Canon EF-S 17-85 f/4-5.6 IS USM and EF-S 18-55 f/3.5-5.6 IS II are presented. A calculation of the distortion values in edge zones was held, which were respectively 43 μm and 51.6 μm. The technique and algorithm of software implementation is described. Possible directions of the

  14. Optical and optoelectronic properties of nanostructures based on wide-bandgap semiconductors

    International Nuclear Information System (INIS)

    Kalden, Joachim

    2010-01-01

    Recently, more and more research is done on nitride nanostructures in order to control the electrical and optical properties in a more sophisticated manner for optimized light-matter-interaction and extraction efficiency. In this context, the work presented in this thesis has been carried out, concentrating on two main topics. One aspect is the characterization of InGaN quantum dots (QDs). QDs possess a unique atom-like density of states for electrons, allowing for generation and manipulation of discrete electronic states. This thesis contains the analysis of QDs embedded in optoelectronic devices such as LEDs. Measurements of the electroluminescence (EL) of QD ensembles as well as single QDs are presented. Especially QD EL obtained at higher temperatures up to 150 K is a main achievement of this work. Furthermore, the photoluminescence (PL) of QD multilayer structures has been examined and discussed in detail. Experiments on the optical amplification in these multilayers have been carried out for the first time, yielding a maximum optical gain of g(max)/(mod)=50/cm. Another main aspect of solid state lighting is the efficient light extraction from light sources. For this purpose, pillar microcavities based on nitrides have been investigated. This type of optical resonator possesses a discrete optical mode structure due to the three-dimensional optical confinement in these structures. For optimal light-matter coupling conditions, this leads to an enhanced extraction efficiency. In this context, studies on QD pillar microcavities (MCs) processed by focused ion beam milling from planar MC structures are presented. After a detailed analysis of the photonic properties of these pillar MCs, a temperature-variation method to tune the cavity in resonance with QD emission is demonstrated, yielding a five-fold enhancement of the extraction efficiency. These experiments were carried out on selenide-based structures which possess a very high structural quality. An alternative

  15. Sealing device

    Science.gov (United States)

    Garcia-Crespo, Andres Jose

    2013-12-10

    A sealing device for sealing a gap between a dovetail of a bucket assembly and a rotor wheel is disclosed. The sealing device includes a cover plate configured to cover the gap and a retention member protruding from the cover plate and configured to engage the dovetail. The sealing device provides a seal against the gap when the bucket assemply is subjected to a centrifugal force.

  16. Microfluidic Device

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey L. (Inventor)

    2017-01-01

    Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.

  17. Gauging device

    International Nuclear Information System (INIS)

    Qurnell, F.D.; Patterson, C.B.

    1979-01-01

    A gauge supporting device for measuring say a square tube comprises a pair of rods or guides in tension between a pair of end members, the end members being spaced apart by a compression member or members. The tensioned guides provide planes of reference for measuring devices moved therealong on a carriage. The device is especially useful for making on site dimensional measurements of components, such as irradiated and therefore radioactive components, that cannot readily be transported to an inspection laboratory. (UK)

  18. Performance and calibration of the CHORUS scintillating fiber tracker and opto-electronics readout system

    International Nuclear Information System (INIS)

    Annis, P.; Aoki, S.; Brunner, J.; De Jong, M.; Fabre, J.P.; Ferreira, R.; Flegel, W.; Frekers, D.; Gregoire, G.; Herin, J.; Kobayashi, M.; Konijn, J.; Lemaitre, V.; Macina, D.; Meijer Drees, R.; Meinhard, H.; Michel, L.; Mommaert, C.; Nakamura, K.; Nakamura, M.; Nakano, T.; Niwa, K.; Niu, E.; Panman, J.; Riccardi, F.; Rondeshagen, D.; Sato, O.; Stefanini, G.; Vander Donckt, M.; Vilain, P.; Wilquet, G.; Winter, K.; Wong, H.T.

    1995-01-01

    An essential component of the CERN WA95/CHORUS experiment is a scintillating fiber tracker system for precise track reconstruction of particles. The tracker design, its opto-electronics readout and calibration system are discussed. Performances of the detector are presented. (orig.)

  19. Studies on the optoelectronic properties of the thermally evaporated tin-doped indium oxide nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Ko-Ying [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, ROC (China); Lin, Liang-Da [Institute of Materials Science and Nanotechnology, Chinese Culture University, Taipei 111, Taiwan, ROC (China); Chang, Li-Wei [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, ROC (China); Shih, Han C., E-mail: hcshih@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, ROC (China); Institute of Materials Science and Nanotechnology, Chinese Culture University, Taipei 111, Taiwan, ROC (China)

    2013-05-15

    Indium oxide (In{sub 2}O{sub 3}) nanorods, nanotowers and tin-doped (Sn:In = 1:100) indium oxide (ITO) nanorods have been fabricated by thermal evaporation. The morphology, microstructure and chemical composition of these three nanoproducts are characterized by FE-SEM, HRTEM and XPS. To further investigate the optoelectronic properties, the I–V curves and cathodoluminescence (CL) spectra are measured. The electrical resistivity of In{sub 2}O{sub 3} nanorods, nanotowers and ITO nanorods are 1.32 kΩ, 0.65 kΩ and 0.063 kΩ, respectively. CL spectra of these three nanoproducts clearly indicate that tin-doped (Sn:In = 1:100) indium oxide (ITO) nanorods cause a blue shift. No doubt ITO nanorods obtain the highest performance among these three nanoproducts, and this also means that Sn-doped In{sub 2}O{sub 3} nanostructures would be the best way to enhance the optoelectronic properties. Additionally, the growing mechanism and the optoelectronic properties of these three nanostructures are discussed. This study is beneficial to the applications of In{sub 2}O{sub 3} nanorods, nanotowers and ITO nanorods in optoelectronic nanodevices.

  20. OSA Trends in Optics and Photonics Series. Volume 13: Ultrafast Electronics and Optoelectronics

    Science.gov (United States)

    1997-01-01

    tomography. Many materials such as plastics, cardboard, wood and rubber have good transparency in the terahertz frequency range. Hence, this new...Ultrafast processes in semiconductors. Introduction Nonlinear Bragg reflector ( NBR ) consists of periodically distributed optical nonlinearity coexisting...with multiple reflection and group-delay dispersion. Recent theoretical analyses showed the potential of NBR in ultrafast optoelectronics such as all

  1. Optoelectronic properties of higher acenes, their BN analogue and substituted derivatives

    International Nuclear Information System (INIS)

    Armaković, Stevan; Armaković, Sanja J.; Holodkov, Vladimir; Pelemiš, Svetlana

    2016-01-01

    We have investigated optoelectronic properties of higher acenes: pentacene, hexacene, heptacene, octacene, nonacene, decacene and their boron-nitride (BN) analogues, within the framework of density functional theory (DFT). We have also investigated the optoelectronic properties of acenes modified by BN substitution. Calculated optoelectronic properties encompasses: oxidation and reduction potentials, electron and hole reorganization energies and energy difference between excited first singlet and triplet states ΔE(S_1−T_1). Oxidation and reduction potentials indicate significantly better stability of BN analogues, comparing with their all-carbon relatives. Although higher acenes possess lower electron and hole reorganization energies, with both best values much lower than 0.1 eV, their BN analogues also have competitive values of reorganization energies, especially for holes for which reorganization energy is also lower than 0.1 eV. On the other hand ΔE(S_1−T_1) is much better for BN analogues, having values that indicate that BN analogues are possible applicable for thermally activated delayed fluorescence. - Highlights: • Optoelectronic properties of structures based on higher acenes have been investigated. • Oxidation and reduction potentials together with reorganization energies are calculated. • TADF is analyzed through calculation of ΔE(S_1−T_1), which is much better for BN analogues. • Reorganization energies of acenes improve with the increase of number of benzene rings.

  2. Optoelectronic properties of higher acenes, their BN analogue and substituted derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Armaković, Stevan, E-mail: stevan.armakovic@df.uns.ac.rs [University of Novi Sad, Faculty of Sciences, Department of Physics, Trg Dositeja Obradovića 4, 21000, Novi Sad (Serbia); Armaković, Sanja J. [University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemistry and Environmental Protection, Trg Dositeja Obradovića 3, 21000, Novi Sad (Serbia); Holodkov, Vladimir [Educons University, Faculty of Sport and Tourism - TIMS, Radnička 30a, 21000, Novi Sad (Serbia); Pelemiš, Svetlana [University of East Sarajevo, Faculty of Technology, Karakaj bb, 75400, Zvornik, Republic of Srpska, Bosnia and Herzegovina (Bosnia and Herzegovina)

    2016-02-15

    We have investigated optoelectronic properties of higher acenes: pentacene, hexacene, heptacene, octacene, nonacene, decacene and their boron-nitride (BN) analogues, within the framework of density functional theory (DFT). We have also investigated the optoelectronic properties of acenes modified by BN substitution. Calculated optoelectronic properties encompasses: oxidation and reduction potentials, electron and hole reorganization energies and energy difference between excited first singlet and triplet states ΔE(S{sub 1}−T{sub 1}). Oxidation and reduction potentials indicate significantly better stability of BN analogues, comparing with their all-carbon relatives. Although higher acenes possess lower electron and hole reorganization energies, with both best values much lower than 0.1 eV, their BN analogues also have competitive values of reorganization energies, especially for holes for which reorganization energy is also lower than 0.1 eV. On the other hand ΔE(S{sub 1}−T{sub 1}) is much better for BN analogues, having values that indicate that BN analogues are possible applicable for thermally activated delayed fluorescence. - Highlights: • Optoelectronic properties of structures based on higher acenes have been investigated. • Oxidation and reduction potentials together with reorganization energies are calculated. • TADF is analyzed through calculation of ΔE(S{sub 1}−T{sub 1}), which is much better for BN analogues. • Reorganization energies of acenes improve with the increase of number of benzene rings.

  3. Concept of Quantum Geometry in Optoelectronic Processes in Solids: Application to Solar Cells.

    Science.gov (United States)

    Nagaosa, Naoto; Morimoto, Takahiro

    2017-07-01

    The concept of topology is becoming more and more relevant to the properties and functions of electronic materials including various transport phenomena and optical responses. A pedagogical introduction is given here to the basic ideas and their applications to optoelectronic processes in solids. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. How phase composition influences optoelectronic and photocatalytic properties of TiO2

    NARCIS (Netherlands)

    Carneiro, J.T.; Carneiro, Joana T.; Savenije, Tom J.; Moulijn, Jacob A.; Mul, Guido

    2011-01-01

    In the present study the ratio of rutile and anatase phases in sol−gel-synthe-sized TiO2 was varied by calcination at temperatures ranging from 500 to 900 °C. Changes in opto-electronic properties were analyzed by time-resolved microwave conductance measurements (TRMC) and evaluated by comparison of

  5. Study of Optoelectronics Properties of Anisotropic Semiconductor Compounds with Ordered Stochiometric Vacancy

    National Research Council Canada - National Science Library

    Roud, Iouri

    2004-01-01

    This report results from a contract tasking loffe Institute as follows: The main aim of the project is to carry out basic research on optoelectronic properties of CdGeAs2 and (Zn,Cd,Hg)(Ga,Al,ln)2(S,Se,Te...

  6. Tetracene-based organic light-emitting transistors: optoelectronic properties and electron injection mechanism

    NARCIS (Netherlands)

    Santato, C.; Capelli, R.; Loi, M.A.; Murgia, M.; Cicoira, F.; Roy, Arunesh; Stallinga, P; Zamboni, R.; Rost, C.; Karg, S.F.; Muccini, M.

    2004-01-01

    Optoelectronic properties of light-emitting field-effect transistors (LETs) fabricated on bottom-contact transistor structures using a tetracene film as charge-transport and light-emitting material are investigated. Electroluminescence generation and transistor current are correlated, and the bias

  7. Tuning Optoelectronic Properties of Ambipolar Organic Light-Emitting Transistors Using a Bulk-Heterojunction Approach

    NARCIS (Netherlands)

    Loi, Maria Antonietta; Rost-Bietsch, Constance; Murgia, Mauro; Karg, Siegfried; Riess, Walter; Muccini, Michele

    2006-01-01

    Bulk-heterojunction engineering is demonstrated as an approach to producing ambipolar organic light-emitting field-effect transistors with tunable electrical and optoelectronic characteristics. The electron and hole mobilities, as well as the electroluminescence intensity, can be tuned over a large

  8. Combined experimental–theoretical study of the optoelectronic properties of non-stoichiometric pyrochlore bismuth titanate

    KAUST Repository

    Noureldine, Dalal; Lardhi, Sheikha F.; Ziani, Ahmed; Harb, Moussab; Cavallo, Luigi; Takanabe, Kazuhiro

    2015-01-01

    A combination of experimental and computational methods was applied to investigate the crystal structure and optoelectronic properties of the non-stoichiometric pyrochlore Bi2−xTi2O7−1.5x. The detailed experimental protocol for both powder and thin

  9. II-VI Narrow-Bandgap Semiconductors for Optoelectronics

    Science.gov (United States)

    Baker, Ian

    The field of narrow-gap II-VI materials is dominated by the compound semiconductor mercury cadmium telluride, (Hg1-x Cd x Te or MCT), which supports a large industry in infrared detectors, cameras and infrared systems. It is probably true to say that HgCdTe is the third most studied semiconductor after silicon and gallium arsenide. Hg1-x Cd x Te is the material most widely used in high-performance infrared detectors at present. By changing the composition x the spectral response of the detector can be made to cover the range from 1 μm to beyond 17 μm. The advantages of this system arise from a number of features, notably: close lattice matching, high optical absorption coefficient, low carrier generation rate, high electron mobility and readily available doping techniques. These advantages mean that very sensitive infrared detectors can be produced at relatively high operating temperatures. Hg1-x Cd x Te multilayers can be readily grown in vapor-phase epitaxial processes. This provides the device engineer with complex doping and composition profiles that can be used to further enhance the electro-optic performance, leading to low-cost, large-area detectors in the future. The main purpose of this chapter is to describe the applications, device physics and technology of II-VI narrow-bandgap devices, focusing on HgCdTe but also including Hg1-x Mn x Te and Hg1-x Zn x Te. It concludes with a review of the research and development programs into third-generation infrared detector technology (so-called GEN III detectors) being performed in centers around the world.

  10. Mixed Dimensional Van der Waals Heterostructures for Opto-Electronics.

    Science.gov (United States)

    Jariwala, Deep

    The isolation of a growing number of two-dimensional (2D) materials has inspired worldwide efforts to integrate distinct 2D materials into van der Waals (vdW) heterostructures. While a tremendous amount of research activity has occurred in assembling disparate 2D materials into ``all-2D'' van der Waals heterostructures, this concept is not limited to 2D materials alone. Given that any passivated, dangling bond-free surface will interact with another via vdW forces, the vdW heterostructure concept can be extended to include the integration of 2D materials with non-2D materials that adhere primarily through noncovalent interactions. In the first part of this talk I will present our work on emerging mixed-dimensional (2D + nD, where n is 0, 1 or 3) heterostructure devices performed at Northwestern University. I will present two distinct examples of gate-tunable p-n heterojunctions 1. Single layer n-type MoS2\\ (2D) combined with p-type semiconducting single walled carbon nanotubes (1D) and 2. Single layer MoS2 combined with 0D molecular semiconductor, pentacene. I will present the unique electrical properties, underlying charge transport mechanisms and photocurrent responses in both the above systems using a variety of scanning probe microscopy techniques as well as computational analysis. This work shows that van der Waals interactions are robust across different dimensionalities of materials and can allow fabrication of semiconductor devices with unique geometries and properties unforeseen in bulk semiconductors. Finally, I will briefly discuss our recent work from Caltech on near-unity absorption in atomically-thin photovoltaic devices. This work is supported by the Materials Research Center at Northwestern University, funded by the National Science Foundation (NSF DMR-1121262) and the Resnick Sustainability Institute at Caltech.

  11. Irradiation tests of optoelectronic components for LHC inner-detectors

    International Nuclear Information System (INIS)

    Dawson, I.; Oglesby, S.J.; Dowell, J.D.; Homer, R.J.; Kenyon, I.R.; Shaylor, H.R.; Wilson, J.A.

    1997-01-01

    Two kinds of optical-link technologies have been investigated for the readout of data at LHC experiments; one based on LEDs and the other on Multi-Quantum-Well modulators. Presented in this paper are the results of irradiating LEDs and MQW modulators with 1 MeV-equivalent neutrons and 24 GeV protons. The devices were biased and the performances of the optical links were monitored throughout the tests. The fluences achieved were ∝5 x 10 14 n cm -2 and ∝6 x 10 13 p cm -2 . (orig.)

  12. Opto-electronic and quantum transport properties of semiconductor nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Sabathil, M.

    2005-01-01

    In this work a novel and efficient method for the calculation of the ballistic transport properties of open semiconductor nanostructures connected to external reservoirs is presented. It is based on the Green's function formalism and reduces the effort to obtain the transmission and the carrier density to a single solution of a hermitian eigenvalue problem with dimensions proportional to the size of the decoupled device and the multiple inversion of a small matrix with dimensions proportional to the size of the contacts to the leads. Using this method, the 4-band GaAs hole transport through a 2-dimensional three-terminal T-junction device, and the resonant tunneling current through a 3-dimensional InAs quantum dot molecule embedded into an InP heterostructure have been calculated. The further extension of the method into a charge self-consistent scheme enables the efficient prediction of the IV-characteristics of highly doped nanoscale field effect transistors in the ballistic regime, including the influence of quasi bound states and the exchange-correlation interaction. Buettiker probes are used to emulate the effect of inelastic scattering on the current for simple 1D devices, systematically analyzing the dependence of the density of states and the resulting self-consistent potential on the scattering strength. The second major topic of this work is the modeling of the optical response of quantum confined neutral and charged excitons in single and coupled self-assembled InGaAs quantum dots. For this purpose the existing device simulator nextnano{sup 3} has been extended to incorporate particle-particle interactions within the means of density functional theory in local density approximation. In this way the exciton transition energies for neutral and charged excitons as a function of an externally applied electric field have been calculated, revealing a systematic reduction of the intrinsic dipole with the addition of extra holes to the exciton, a finding

  13. Optically controlled multiple switching operations of DNA biopolymer devices

    International Nuclear Information System (INIS)

    Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu; Fruk, Ljiljana; Hung, Yu-Chueh

    2015-01-01

    We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices

  14. Optically controlled multiple switching operations of DNA biopolymer devices

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Fruk, Ljiljana [Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA (United Kingdom); Hung, Yu-Chueh, E-mail: ychung@ee.nthu.edu.tw [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2015-12-21

    We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices.

  15. Vertical MoSe2-MoO x p-n heterojunction and its application in optoelectronics

    Science.gov (United States)

    Chen, Xiaoshuang; Liu, Guangbo; Hu, Yunxia; Cao, Wenwu; Hu, PingAn; Hu, Wenping

    2018-01-01

    The hybrid n-type 2D transition-metal dichalcogenide (TMD)/p-type oxide van der Waals (vdW) heterojunction nanosheets consist of 2D layered MoSe2 (the n-type 2D material) and MoO x (the p-type oxide) which are grown on SiO2/Si substrates for the first time via chemical vapor deposition technique, displaying the regular hexagon structures with the average length dimension of sides of ˜8 μm. Vertical MoSe2-MoO x p-n heterojunctions demonstrate obviously current-rectifying characteristic, and it can be tuned via gate voltage. What is more, the photodetector based on vertical MoSe2-MoO x heterojunctions displays optimal photoresponse behavior, generating the responsivity, detectivity, and external quantum efficiency to 3.4 A W-1, 0.85 × 108 Jones, and 1665.6%, respectively, at V ds = 5 V with the light wavelength of 254 nm under 0.29 mW cm-2. These results furnish a building block on investigating the flexible and transparent properties of vdW and further optimizing the structure of the devices for better optoelectronic and electronic performance.

  16. Evaluation of the structural, optical and electrical properties of AZO thin films prepared by chemical bath deposition for optoelectronics

    Science.gov (United States)

    Kumar, K. Deva Arun; Valanarasu, S.; Rosario, S. Rex; Ganesh, V.; Shkir, Mohd.; Sreelatha, C. J.; AlFaify, S.

    2018-04-01

    Aluminum doped zinc oxide (AZO) thin films for electrode applications were deposited on glass substrates using chemical bath deposition (CBD) method. The influence of deposition time on the structural, morphological, and opto-electrical properties of AZO films were investigated. Structural studies confirmed that all the deposited films were hexagonal wurtzite structure with polycrystalline nature and exhibited (002) preferential orientation. There is no other impurity phases were detected for different deposition time. Surface morphological images shows the spherically shaped grains are uniformly arranged on to the entire film surface. The EDS spectrum confirms the presence of Zn, O and Al elements in deposited AZO film. The observed optical transmittance is high (87%) in the visible region, and the calculated band gap value is 3.27 eV. In this study, the transmittance value is decreased with increasing deposition time. The room temperature PL spectrum exposed that AZO thin film deposited at (60 min) has good optical quality with less defect density. The minimum electrical resistivity and maximum carrier concentration values were observed as 8.53 × 10-3(Ω cm) and 3.53 × 1018 cm-3 for 60 min deposited film, respectively. The obtained figure of merit (ϕ) value 3.05 × 10-3(Ω/sq)- 1 is suggested for an optoelectronic device.

  17. A Comparative Study of Physiological Monitoring with a Wearable Opto-Electronic Patch Sensor (OEPS for Motion Reduction

    Directory of Open Access Journals (Sweden)

    Abdullah Alzahrani

    2015-06-01

    Full Text Available This paper presents a comparative study in physiological monitoring between a wearable opto-electronic patch sensor (OEPS comprising a three-axis Microelectromechanical systems (MEMs accelerometer (3MA and commercial devices. The study aims to effectively capture critical physiological parameters, for instance, oxygen saturation, heart rate, respiration rate and heart rate variability, as extracted from the pulsatile waveforms captured by OEPS against motion artefacts when using the commercial probe. The protocol involved 16 healthy subjects and was designed to test the features of OEPS, with emphasis on the effective reduction of motion artefacts through the utilization of a 3MA as a movement reference. The results show significant agreement between the heart rates from the reference measurements and the recovered signals. Significance of standard deviation and error of mean yield values of 2.27 and 0.65 beats per minute, respectively; and a high correlation (0.97 between the results of the commercial sensor and OEPS. T, Wilcoxon and Bland-Altman with 95% limit of agreement tests were also applied in the comparison of heart rates extracted from these sensors, yielding a mean difference (MD: 0.08. The outcome of the present work incites the prospects of OEPS on physiological monitoring during physical activities.

  18. High energy electron irradiation effects on Ga-doped ZnO thin films for optoelectronic space applications

    Science.gov (United States)

    Serrao, Felcy Jyothi; Sandeep, K. M.; Bhat, Shreesha; Dharmaprakash, S. M.

    2018-03-01

    Gallium-doped ZnO (GZO) thin films of thickness 394 nm were prepared by a simple, cost-effective sol-gel spin coating method. The effect of 8 MeV electron beam irradiation with different irradiation doses ranging from 0 to 10 kGy on the structural, optical and electrical properties was investigated. Electron irradiation influences the changes in the structural properties and surface morphology of GZO thin films. X-ray diffraction analysis showed that the polycrystalline nature of the GZO films is unaffected by the high energy electron irradiation. The grain size and the surface roughness were found maximum for the GZO film irradiated with 10 kGy electron dosage. The average transmittance of GZO thin films decreased after electron irradiation. The optical band gap of Ga-doped ZnO films was decreased with the increase in the electron dosage. The electrical resistivity of GZO films decreased from 4.83 × 10-3 to 8.725 × 10-4 Ω cm, when the electron dosage was increased from 0 to 10 kGy. The variation in the optical and electrical properties in the Ga-doped ZnO thin films due to electron beam irradiation in the present study is useful in deciding their compatibility in optoelectronic device applications in electron radiation environment.

  19. Ab initio study of the bandgap engineering of Al1−xGaxN for optoelectronic applications

    KAUST Repository

    Amin, B.; Ahmad, Iftikhar; Maqbool, M.; Goumri-Said, S.; Ahmad, R.

    2011-01-01

    A theoretical study of Al1−xGaxN, based on the full-potential linearized augmented plane wave method, is used to investigate the variations in the bandgap,optical properties, and nonlinear behavior of the compound with the change in the Ga concentration. It is found that the bandgap decreases with the increase in Ga. A maximum value of 5.50 eV is determined for the bandgap of pure AlN, which reaches a minimum value of 3.0 eV when Al is completely replaced by Ga. The static index of refraction and dielectric constant decreases with the increase in the bandgap of the material, assigning a high index of refraction to pure GaN when compared to pure AlN. The refractive index drops below 1 for higher energy photons, larger than 14 eV. The group velocity of these photons is larger than the vacuum velocity of light. This astonishing result shows that at higher energies the optical properties of the material shifts from linear to nonlinear. Furthermore, frequency dependent reflectivity and absorption coefficients show that peak values of the absorption coefficient and reflectivity shift toward lower energy in the ultraviolet (UV) spectrum with the increase in Ga concentration. This comprehensive theoretical study of the optoelectronic properties predicts that the material can be effectively used in the optical devices working in the visible and UV spectrum.

  20. Optoelectronic Properties and Structural Characterization of GaN Thick Films on Different Substrates through Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Wei-Kai Wang

    2017-01-01

    Full Text Available Approximately 4-μm-thick GaN epitaxial films were directly grown onto a GaN/sapphire template, sapphire, Si(111, and Si(100 substrates by high-temperature pulsed laser deposition (PLD. The influence of the substrate type on the crystalline quality, surface morphology, microstructure, and stress states was investigated by X-ray diffraction (XRD, photoluminescence (PL, atomic force microscopy (AFM, transmission electron microscopy (TEM, and Raman spectroscopy. Raman scattering spectral analysis showed a compressive film stress of −0.468 GPa for the GaN/sapphire template, whereas the GaN films on sapphire, Si(111, and Si(100 exhibited a tensile stress of 0.21, 0.177, and 0.081 GPa, respectively. Comparative analysis indicated the growth of very close to stress-free GaN on the Si(100 substrate due to the highly directional energetic precursor migration on the substrate’s surface and the release of stress in the nucleation of GaN films during growth by the high-temperature (1000 °C operation of PLD. Moreover, TEM images revealed that no significant GaN meltback (Ga–Si etching process was found in the GaN/Si sample surface. These results indicate that PLD has great potential for developing stress-free GaN templates on different substrates and using them for further application in optoelectronic devices.

  1. Ab initio study of the bandgap engineering of Al1−xGaxN for optoelectronic applications

    KAUST Repository

    Amin, B.

    2011-01-19

    A theoretical study of Al1−xGaxN, based on the full-potential linearized augmented plane wave method, is used to investigate the variations in the bandgap,optical properties, and nonlinear behavior of the compound with the change in the Ga concentration. It is found that the bandgap decreases with the increase in Ga. A maximum value of 5.50 eV is determined for the bandgap of pure AlN, which reaches a minimum value of 3.0 eV when Al is completely replaced by Ga. The static index of refraction and dielectric constant decreases with the increase in the bandgap of the material, assigning a high index of refraction to pure GaN when compared to pure AlN. The refractive index drops below 1 for higher energy photons, larger than 14 eV. The group velocity of these photons is larger than the vacuum velocity of light. This astonishing result shows that at higher energies the optical properties of the material shifts from linear to nonlinear. Furthermore, frequency dependent reflectivity and absorption coefficients show that peak values of the absorption coefficient and reflectivity shift toward lower energy in the ultraviolet (UV) spectrum with the increase in Ga concentration. This comprehensive theoretical study of the optoelectronic properties predicts that the material can be effectively used in the optical devices working in the visible and UV spectrum.

  2. Photonic Crystals Towards Nanoscale Photonic Devices

    CERN Document Server

    Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexei; Pagnoux, Dominique

    2008-01-01

    Just like the periodical crystalline potential in solid state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as cages for storing, filtering or guiding light at the wavelength scale paves the way to the realization of optical and optoelectronic devices with ultimate properties and dimensions. This will contribute towards meeting the demands for greater miniaturization imposed by the processing of an ever increasing number of data. Photonic Crystals will provide students and researchers from different fields with the theoretical background required for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, ranging from optics to microwaves, where photonic crystals have found application. As such, it aims at building bridges between...

  3. Photonic Crystals Towards Nanoscale Photonic Devices

    CERN Document Server

    Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexis

    2005-01-01

    Just like the periodical crystalline potential in solid-state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as a cage for storing, filtering or guiding light at the wavelength scale thus paves the way to the realisation of optical and optoelectronic devices with ultimate properties and dimensions. This should contribute toward meeting the demands for a greater miniaturisation that the processing of an ever increasing number of data requires. Photonic Crystals intends at providing students and researchers from different fields with the theoretical background needed for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, from optics to microwaves, where photonic crystals have found applications. As such, it aims at building brid...

  4. Optimization of Quantum-Dot Molecular Beam Epitaxy for Broad Spectral Bandwidth Devices

    KAUST Repository

    Majid, Mohammed Abdul

    2012-12-01

    The optimization of the key growth parameters for broad spectral bandwidth devices based on quantum dots is reported. A combination of atomic force microscopy, photoluminescence of test samples, and optoelectronic characterization of superluminescent diodes (SLDs) is used to optimize the growth conditions to obtain high-quality devices with large spectral bandwidth, radiative efficiency (due to a reduced defective-dot density), and thus output power. The defective-dot density is highlighted as being responsible for the degradation of device performance. An SLD device with 160 nm of bandwidth centered at 1230 nm is demonstrated.

  5. Optimization of Quantum-Dot Molecular Beam Epitaxy for Broad Spectral Bandwidth Devices

    KAUST Repository

    Majid, Mohammed Abdul; Hugues, M.; Vézian, S.; Childs, D. T. D.; Hogg, R. A.

    2012-01-01

    The optimization of the key growth parameters for broad spectral bandwidth devices based on quantum dots is reported. A combination of atomic force microscopy, photoluminescence of test samples, and optoelectronic characterization of superluminescent diodes (SLDs) is used to optimize the growth conditions to obtain high-quality devices with large spectral bandwidth, radiative efficiency (due to a reduced defective-dot density), and thus output power. The defective-dot density is highlighted as being responsible for the degradation of device performance. An SLD device with 160 nm of bandwidth centered at 1230 nm is demonstrated.

  6. Fusion devices

    International Nuclear Information System (INIS)

    Fowler, T.K.

    1977-01-01

    Three types of thermonuclear fusion devices currently under development are reviewed for an electric utilities management audience. Overall design features of laser fusion, tokamak, and magnetic mirror type reactors are described and illustrated. Thrusts and trends in current research on these devices that promise to improve performance are briefly reviewed. Twenty photographs and drawings are included

  7. BRAKE DEVICE

    Science.gov (United States)

    O'Donnell, T.J.

    1959-03-10

    A brake device is described for utilization in connection with a control rod. The device comprises a pair of parallelogram link mechanisms, a control rod moveable rectilinearly therebetween in opposite directions, and shoes resiliently supported by the mechanism for frictional engagement with the control rod.

  8. Optical absorption and electrical properties of MPc (M =Fe, Cu, Zn)-TCNQ interfaces for optoelectronic applications

    Science.gov (United States)

    Sánchez Vergara, M. E.; Medrano Gallardo, D.; Vera Estrada, I. L.; Jiménez Sandoval, O.

    2018-04-01

    all three devices manufactured, MMFe, MMCu and MMZn, are of potential use in optoelectronics. The doping effect of TCNQ favors the electronic transport, most likely due to the formation of conduction channels caused by the anisotropy induced by the dopant.

  9. PLASMA DEVICE

    Science.gov (United States)

    Gow, J.D.; Wilcox, J.M.

    1961-12-26

    A device is designed for producing and confining highenergy plasma from which neutrons are generated in copious quantities. A rotating sheath of electrons is established in a radial electric field and axial magnetic field produced within the device. The electron sheath serves as a strong ionizing medium to gas introdueed thereto and also functions as an extremely effective heating mechanism to the resulting plasma. In addition, improved confinement of the plasma is obtained by ring magnetic mirror fields produced at the ends of the device. Such ring mirror fields are defined by the magnetic field lines at the ends of the device diverging radially outward from the axis of the device and thereafter converging at spatial annular surfaces disposed concentrically thereabout. (AFC)

  10. Chemical vapor deposition growth of single-crystalline cesium lead halide microplatelets and heterostructures for optoelectronic applications

    Institute of Scientific and Technical Information of China (English)

    Yiliu Wang; Xun Guan; Dehui Li; Hung-Chieh Cheng; Xidong Duan; Zhaoyang Lin; Xiangfeng Duan

    2017-01-01

    Orgaruc-inorganic hybrid halide perovskites,such as CH3NH3PbI3,have emerged as an exciting class of materials for solar photovoltaic applications;however,they are currently plagued by insufficient environmental stability.To solve this issue,all-inorganic halide perovskites have been developed and shown to exhibit significantly improved stability.Here,we report a single-step chemical vapor deposition growth of cesium lead halide (CsPbX3) microcrystals.Optical microscopy studies show that the resulting perovskite crystals predominantly adopt a square-platelet morphology.Powder X-ray diffraction (PXRD) studies of the resulting crystals demonstrate a highly crystalline nature,with CsPbC13,CsPbBr3,and CsPbI3 showing tetragonal,monoclinic,and orthorhombic phases,respectively.Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies show that the resulting platelets exhibit well-faceted structures with lateral dimensions of the order of 10-50 μm,thickness around 1 μm,and ultra-smooth surface,suggesting the absence of obvious grain boundaries and the single-crystalline nature of the individual microplatelets.Photoluminescence (PL) images and spectroscopic studies show a uniform and intense emission consistent with the expected band edge transition.Additionally,PL images show brighter emission around the edge of the platelets,demonstrating a wave-guiding effect in high-quality crystals.With a well-defined geometry and ultra-smooth surface,the square platelet structure can function as a whispering gallery mode cavity with a quality factor up to 2,863 to support laser emission at room temperature.Finally,we demonstrate that such microplatelets can be readily grown on a variety of substrates,including silicon,graphene,and other two-dimensional materials such as molybdenum disulfide,which can readily allow the construction of heterostructure optoelectronic devices,including a graphene/perovskite/ graphene vertically-stacked photodetector with

  11. Transparent Electrodes with Nanotubes and Graphene for Printed Optoelectronic Applications

    Directory of Open Access Journals (Sweden)

    Marcin Słoma

    2014-01-01

    Full Text Available We report here on printed electroluminescent structures containing transparent electrodes made of carbon nanotubes and graphene nanoplatelets. Screen-printing and spray-coating techniques were employed. Electrodes and structures were examined towards optical parameters using spectrophotometer and irradiation meter. Electromechanical properties of transparent electrodes are exterminated with cyclical bending test. Accelerated aging process was conducted according to EN 62137 standard for reliability tests of electronics. We observed significant negative influence of mechanical bending on sheet resistivity of ITO, while resistivity of nanotube and graphene based electrodes remained stable. Aging process has also negative influence on ITO based structures resulting in delamination of printed layers, while those based on carbon nanomaterials remained intact. We observe negligible changes in irradiation for structures with carbon nanotube electrodes after accelerated aging process. Such materials demonstrate a high application potential in general purpose electroluminescent devices.

  12. Study of a thiophene-based polymer for optoelectronic applications

    International Nuclear Information System (INIS)

    Cheylan, S.; Fraleoni-Morgera, A.; Puigdollers, J.; Voz, C.; Setti, L.; Alcubilla, R.; Badenes, G.; Costa-Bizzarri, P.; Lanzi, M.

    2006-01-01

    A thiophene-based conjugated polymer bearing a cyano group (-CN) as a side chain substituent was successfully synthesized. The polymer evidences an excellent film ability from various organic solvents as well as an enhanced photoluminescence. The polymer has been characterized optically (Fourier Transformed Infrared spectroscopy, absorption and photoluminescence) in solution and in film, while X-ray diffraction measurements (XRD) of thin films were performed to investigate its bulk morphological features. From the absorption edge of the spectrum of a thin polymer film, the optical band gap of the polymer is estimated to be 2.0 eV, which corresponds to orange emission. Furthermore, a single layer light emitting diode (LED) was fabricated. The device produced bright stable electroluminescence at room temperature. All of the results indicate that this polymer is a promising emissive material for application in polymeric LEDs

  13. Probing Local Heterogeneity in the Optoelectronic Properties of Organic-Inorganic Perovskites Using Fluorescence Microscopy

    Science.gov (United States)

    De Quilettes, Dane W.

    -of-magnitude reduction in trap state density. Next, we studied the effects of a series of post-deposition ligand treatments on the PL of polycrystalline methylammonium lead triiodide perovskite thin films. Using glow discharge optical emission spectroscopy (GDOES) and nuclear magnetic resonance (NMR) spectroscopy, we showed that the ligands are incorporated primarily at the film surface and are acting as electron donors. These results indicate it is possible to obtain thin film PL lifetime and PLQE values that are comparable to those from single crystals by control over surface chemistry. Finally, we further characterized these TOPO treated films to show, with respect to material bandgap, these passivated films could demonstrate quasi-Fermi level splittings comparable to the highest performing GaAs solar cells, reaching 96% of the Shockley-Queisser limit. Importantly, we reported internal photoluminescence quantum efficiency values of 92% under one sun illumination intensity, which are the highest values achieved to date. These results suggest that the material optoelectronic quality has been nearly optimized and further increases in voltage and device efficiency will be obtained by integrating these types of surface passivation schemes into charge carrier selective interfaces. (Abstract shortened by ProQuest.).

  14. Proceedings of the first international conference on indium phosphide and related materials for advanced electronic and optical devices

    International Nuclear Information System (INIS)

    Singh, R.; Messick, L.J.

    1989-01-01

    This book contains the proceedings of the first international conference on indium phosphide and related materials for advanced electronic and optical devices. Topics covered include: Growth and characterization of bulk and epitaxial films, Passivation technology, Processing technology, High speed optoelectronic integrated circuits, and Solar cells

  15. Optoelectronic Performance Variations in InGaN/GaN Multiple-Quantum-Well Light-Emitting Diodes: Effects of Potential Fluctuation.

    Science.gov (United States)

    Islam, Abu Bashar Mohammad Hamidul; Shim, Jong-In; Shin, Dong-Soo

    2018-05-07

    We investigate the cause of the optoelectronic performance variations in InGaN/GaN multiple-quantum-well blue light-emitting diodes, using three different samples from an identical wafer grown on a c -plane sapphire substrate. Various macroscopic measurements have been conducted, revealing that with increasing strain in the quantum wells (QWs), the crystal quality improves with an increasing peak internal quantum efficiency while the droop becomes more severe. We propose to explain these variations using a model where the in-plane local potential fluctuation in QWs is considered. Our work is contrasted with prior works in that macroscopic measurements are utilized to find clues on the microscopic changes and their impacts on the device performances, which has been rarely attempted.

  16. Asymmetric Supercapacitor Electrodes and Devices.

    Science.gov (United States)

    Choudhary, Nitin; Li, Chao; Moore, Julian; Nagaiah, Narasimha; Zhai, Lei; Jung, Yeonwoong; Thomas, Jayan

    2017-06-01

    The world is recently witnessing an explosive development of novel electronic and optoelectronic devices that demand more-reliable power sources that combine higher energy density and longer-term durability. Supercapacitors have become one of the most promising energy-storage systems, as they present multifold advantages of high power density, fast charging-discharging, and long cyclic stability. However, the intrinsically low energy density inherent to traditional supercapacitors severely limits their widespread applications, triggering researchers to explore new types of supercapacitors with improved performance. Asymmetric supercapacitors (ASCs) assembled using two dissimilar electrode materials offer a distinct advantage of wide operational voltage window, and thereby significantly enhance the energy density. Recent progress made in the field of ASCs is critically reviewed, with the main focus on an extensive survey of the materials developed for ASC electrodes, as well as covering the progress made in the fabrication of ASC devices over the last few decades. Current challenges and a future outlook of the field of ASCs are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. A whole-process progressive training mode to foster optoelectronic students' innovative practical ability

    Science.gov (United States)

    Zhong, Hairong; Xu, Wei; Hu, Haojun; Duan, Chengfang

    2017-08-01

    This article analyzes the features of fostering optoelectronic students' innovative practical ability based on the knowledge structure of optoelectronic disciplines, which not only reveals the common law of cultivating students' innovative practical ability, but also considers the characteristics of the major: (1) The basic theory is difficult, and the close combination of science and technology is obvious; (2)With the integration of optics, mechanics, electronics and computer, the system technology is comprehensive; (3) It has both leading-edge theory and practical applications, so the benefit of cultivating optoelectronic students is high ; (4) The equipment is precise and the practice is costly. Considering the concept and structural characteristics of innovative and practical ability, and adhering to the idea of running practice through the whole process, we put forward the construction of three-dimensional innovation and practice platform which consists of "Synthetically Teaching Laboratory + Innovation Practice Base + Scientific Research Laboratory + Major Practice Base + Joint Teaching and Training Base", and meanwhile build a whole-process progressive training mode to foster optoelectronic students' innovative practical ability, following the process of "basic experimental skills training - professional experimental skills training - system design - innovative practice - scientific research project training - expanded training - graduation project": (1) To create an in - class practical ability cultivation environment that has distinctive characteristics of the major, with the teaching laboratory as the basic platform; (2) To create an extra-curricular innovation practice activities cultivation environment that is closely linked to the practical application, with the innovation practice base as a platform for improvement; (3) To create an innovation practice training cultivation environment that leads the development of cutting-edge, with the scientific

  18. Sealing devices

    International Nuclear Information System (INIS)

    Coulson, R.A.

    1980-01-01

    A sealing device for minimising the leakage of toxic or radioactive contaminated environments through a biological shield along an opening through which a flexible component moves that penetrates the shield. The sealing device comprises an outer tubular member which extends over a length not less than the maximum longitudinal movement of the component along the opening. An inner sealing block is located intermediate the length of the component by connectors and is positioned in the bore of the outer tubular member to slide in the bore and effect a seal over the entire longitudinal movement of the component. The cross-section of the device may be circular and the block may be of polytetrafluoroethylene or of nylon impregnated with molybdenum or may be metallic. A number of the sealing devices may be combined into an assembly for a plurality of adjacent longitudinally movable components, each adapted to sustain a tensile load, providing the various drives of a master-slave manipulator. (author)

  19. Optoelectronics applications in multimedia shooting training systems: SPARTAN

    Science.gov (United States)

    Glogowski, Tomasz; Hlosta, Pawel; Stepniak, Slawomir; Swiderski, Waldemar

    2017-10-01

    Multimedia shooting training systems are increasingly being used in the training of security staff and uniformed services. An advanced practicing-training system SPARTAN for simulation of small arms shooting has been designed and manufactured by Autocomp Management Ltd. and Military Institute of Armament Technology for the Polish Ministry of National Defence. SPARTAN is a stationary device designed to teach, monitor and evaluate the targeting of small arms and to prepare soldiers for: • firing the live ammunition at open ranges for combat targets and silhouettes • detection, classification and engagement of real targets upon different terrains, weather conditions and periods during the day • team work as a squad during the mission by using different types of arms • suitable reactions in untypical scenarios. Placed in any room the training set consists of: • the projection system that generates realistic 3D imaging of the battlefield (such as combat shooting range) in high-resolution • system that tracks weapons aiming points • sound system which delivers realistic mapping of acoustic surroundings • operator station with which the training is conducted and controlled • central processing unit based on PC computers equipped with specialist software realizing individual system functions • units of smart weapons equipped with radio communication modules, injection laser diodes and pneumatic reloading system. The system make possible training by firing in dynamic scenarios, using combat weapons and live ammunition against visible targets moving on a screen. The use of infrared camera for detecting the position of impact of a projectile.

  20. Creation of hybrid optoelectronic systems for document identification

    Science.gov (United States)

    Muravsky, Leonid I.; Voronyak, Taras I.; Kulynych, Yaroslav P.; Maksymenko, Olexander P.; Pogan, Ignat Y.

    2001-06-01

    Use of security devices based on a joint transform correlator (JTC) architecture for identification of credit cards and other products is very promising. The experimental demonstration of the random phase encoding technique for security verification shows that hybrid JTCs can be successfully utilized. The random phase encoding technique provides a very high protection level of products and things to be identified. However, the realization of this technique is connected with overcoming of the certain practical problems. To solve some of these problems and simultaneously to improve the security of documents and other products, we propose to use a transformed phase mask (TPM) as an input object in an optical correlator. This mask is synthesized from a random binary pattern (RBP), which is directly used to fabricate a reference phase mask (RPM). To obtain the TPM, we previously separate the RBP on a several parts (for example, K parts) of an arbitrary shape and further fabricate the TPM from this transformed RBP. The fabricated TPM can be bonded as the optical mark to any product or thing to be identified. If the RPM and the TPM are placed on the optical correlator input, the first diffracted order of the output correlation signal is containing the K narrow autocorrelation peaks. The distances between the peaks and the peak's intensities can be treated as the terms of the identification feature vector (FV) for the TPM identification.

  1. New Optoelectronic Technology Simplified for Organic Light Emitting Diode (OLED

    Directory of Open Access Journals (Sweden)

    Andre F. S. Guedes

    2014-06-01

    Full Text Available The development of Organic Light Emitting Diode (OLED, using an optically transparent substrate material and organic semiconductor materials, has been widely utilized by the electronic industry when producing new technological products. The OLED are the base Poly (3,4-ethylenedioxythiophene, PEDOT, and Polyaniline, PANI, were deposited in Indium Tin Oxide, ITO, and characterized by UV-Visible Spectroscopy (UV-Vis, Optical Parameters (OP and Scanning Electron Microscopy (SEM. In addition, the thin film obtained by the deposition of PANI, prepared in perchloric acid solution, was identified through PANI-X1. The result obtained by UV-Vis has demonstrated that the Quartz/ITO/PEDOT/PANI-X1 layer does not have displacement of absorption for wavelengths greaters after spin-coating and electrodeposition. Thus, the spectral irradiance of the OLED informed the irradiance of 100 W/m2, and this result, compared with the standard Light Emitting Diode (LED, has indicated that the OLED has higher irradiance. After 1000 hours of electrical OLED tests, the appearance of nanoparticles visible for images by SEM, to the migration process of organic semiconductor materials, was present, then. Still, similar to the phenomenon of electromigration observed in connections and interconnections of microelectronic devices, the results have revealed a new mechanism of migration, which raises the passage of electric current in OLED.

  2. Ferroelectric devices

    CERN Document Server

    Uchino, Kenji

    2009-01-01

    Updating its bestselling predecessor, Ferroelectric Devices, Second Edition assesses the last decade of developments-and setbacks-in the commercialization of ferroelectricity. Field pioneer and esteemed author Uchino provides insight into why this relatively nascent and interdisciplinary process has failed so far without a systematic accumulation of fundamental knowledge regarding materials and device development.Filling the informational void, this collection of information reviews state-of-the-art research and development trends reflecting nano and optical technologies, environmental regulat

  3. Electrical Contacts in Monolayer Arsenene Devices.

    Science.gov (United States)

    Wang, Yangyang; Ye, Meng; Weng, Mouyi; Li, Jingzhen; Zhang, Xiuying; Zhang, Han; Guo, Ying; Pan, Yuanyuan; Xiao, Lin; Liu, Junku; Pan, Feng; Lu, Jing

    2017-08-30

    Arsenene, arsenic analogue of graphene, as an emerging member of two-dimensional semiconductors (2DSCs), is quite promising in next-generation electronic and optoelectronic applications. The metal electrical contacts play a vital role in the charge transport and photoresponse processes of nanoscale 2DSC devices and even can mask the intrinsic properties of 2DSCs. Here, we present a first comprehensive study of the electrical contact properties of monolayer (ML) arsenene with different electrodes by using ab initio electronic calculations and quantum transport simulations. Schottky barrier is always formed with bulk metal contacts owing to the Fermi level pinning (pinning factor S = 0.33), with electron Schottky barrier height (SBH) of 0.12, 0.21, 0.25, 0.35, and 0.50 eV for Sc, Ti, Ag, Cu, and Au contacts and hole SBH of 0.75 and 0.78 eV for Pd and Pt contacts, respectively. However, by contact with 2D graphene, the Fermi level pinning effect can be reduced due to the suppression of metal-induced gap states. Remarkably, a barrier free hole injection is realized in ML arsenene device with graphene-Pt hybrid electrode, suggestive of a high device performance in such a ML arsenene device. Our study provides a theoretical foundation for the selection of favorable electrodes in future ML arsenene devices.

  4. Full space device optimization for solar cells.

    Science.gov (United States)

    Baloch, Ahmer A B; Aly, Shahzada P; Hossain, Mohammad I; El-Mellouhi, Fedwa; Tabet, Nouar; Alharbi, Fahhad H

    2017-09-20

    Advances in computational materials have paved a way to design efficient solar cells by identifying the optimal properties of the device layers. Conventionally, the device optimization has been governed by single or double descriptors for an individual layer; mostly the absorbing layer. However, the performance of the device depends collectively on all the properties of the material and the geometry of each layer in the cell. To address this issue of multi-property optimization and to avoid the paradigm of reoccurring materials in the solar cell field, a full space material-independent optimization approach is developed and presented in this paper. The method is employed to obtain an optimized material data set for maximum efficiency and for targeted functionality for each layer. To ensure the robustness of the method, two cases are studied; namely perovskite solar cells device optimization and cadmium-free CIGS solar cell. The implementation determines the desirable optoelectronic properties of transport mediums and contacts that can maximize the efficiency for both cases. The resulted data sets of material properties can be matched with those in materials databases or by further microscopic material design. Moreover, the presented multi-property optimization framework can be extended to design any solid-state device.

  5. Design of a dual-axis optoelectronic level for precision angle measurements

    International Nuclear Information System (INIS)

    Fan, Kuang-Chao; Wang, Tsung-Han; Lin, Sheng-Yi; Liu, Yen-Chih

    2011-01-01

    The accuracy of machine tools is mainly determined by angular errors during linear motion according to the well-known Abbe principle. Precision angle measurement is important to precision machines. This paper presents the theory and experiments of a new dual-axis optoelectronic level with low cost and high precision. The system adopts a commercial DVD pickup head as the angle sensor in association with the double-layer pendulum mechanism for two-axis swings, respectively. In data processing with a microprocessor, the measured angles of both axes can be displayed on an LCD or exported to an external PC. Calibrated by a triple-beam laser angular interferometer, the error of the dual-axis optoelectronic level is better than ±0.7 arcsec in the measuring range of ±30 arcsec, and the settling time is within 0.5 s. Experiments show the applicability to the inspection of precision machines

  6. Two-dimensional gold nanoparticle arrays. A platform for molecular optoelectronics

    Energy Technology Data Exchange (ETDEWEB)

    Mangold, Markus Andreas

    2011-11-15

    In my research, I study the optoelectronic properties of two-dimensional, hexagonal gold nanoparticle arrays formed by self-assembly. When the nanoparticle arrays are embedded in a matrix of alkane thiols, the photoresponse is dominated by a bolometric conductance increase. At room temperature, I observe a strong enhancement of the bolometric photoconductance when the surface plasmon resonance of the nanoparticles is excited. At cryogenic temperatures, the bolometric conductance enhancement leads to a redistribution of the potential landscape which dominates the optoelectronic response of the nanoparticle arrays. When optically active oligo(phenylene vinylene) (OPV) molecules are covalently bound to the nanoparticles, an increased photoconductance due to the resonant excitation of the OPV is observed. The results suggest that the charge carriers, which are resonantly excited in the OPV molecules, directly contribute to the current flow through the nanoparticle arrays. Thus, the conductance of OPV in its excited state is measured in the presented experiments. (orig.)

  7. Molecular coatings of nitride semiconductors for optoelectronics, electronics, and solar energy harvesting

    KAUST Repository

    Ng, Tien Khee; Zhao, Chao; Priante, Davide; Ooi, Boon S.; Hussein, Mohamed Ebaid Abdrabou

    2018-01-01

    Gallium nitride based semiconductors are provided having one or more passivated surfaces. The surfaces can have a plurality of thiol compounds attached thereto for enhancement of optoelectronic properties and/or solar water splitting properties. The surfaces can also include wherein the surface has been treated with chemical solution for native oxide removal and / or wherein the surface has attached thereto a plurality of nitrides, oxides, insulating compounds, thiol compounds, or a combination thereof to create a treated surface for enhancement of optoelectronic properties and / or solar water splitting properties. Methods of making the gallium nitride based semiconductors are also provided. Methods can include cleaning a native surface of a gallium nitride semiconductor to produce a cleaned surface, etching the cleaned surface to remove oxide layers on the surface, and applying single or multiple coatings of nitrides, oxides, insulating compounds, thiol compounds, or a combination thereof attached to the surface.

  8. Molecular coatings of nitride semiconductors for optoelectronics, electronics, and solar energy harvesting

    KAUST Repository

    Ng, Tien Khee

    2018-02-01

    Gallium nitride based semiconductors are provided having one or more passivated surfaces. The surfaces can have a plurality of thiol compounds attached thereto for enhancement of optoelectronic properties and/or solar water splitting properties. The surfaces can also include wherein the surface has been treated with chemical solution for native oxide removal and / or wherein the surface has attached thereto a plurality of nitrides, oxides, insulating compounds, thiol compounds, or a combination thereof to create a treated surface for enhancement of optoelectronic properties and / or solar water splitting properties. Methods of making the gallium nitride based semiconductors are also provided. Methods can include cleaning a native surface of a gallium nitride semiconductor to produce a cleaned surface, etching the cleaned surface to remove oxide layers on the surface, and applying single or multiple coatings of nitrides, oxides, insulating compounds, thiol compounds, or a combination thereof attached to the surface.

  9. Problems of systems dataware using optoelectronic measuring means of linear displacement

    Science.gov (United States)

    Bazykin, S. N.; Bazykina, N. A.; Samohina, K. S.

    2017-10-01

    Problems of the dataware of the systems with the use of optoelectronic means of the linear displacement are considered in the article. The classification of the known physical effects, realized by the means of information-measuring systems, is given. The organized analysis of information flows in technical systems from the standpoint of determination of inaccuracies of measurement and management was conducted. In spite of achieved successes in automation of machine-building and instruments-building equipment in the field of dataware of the technical systems, there are unresolved problems, concerning the qualitative aspect of the production process. It was shown that the given problem can be solved using optoelectronic lazer information-measuring systems. Such information-measuring systems are capable of not only executing the measuring functions, but also solving the problems of management and control during processing, thereby guaranteeing the quality of final products.

  10. Graphene and Carbon-Nanotube Nanohybrids Covalently Functionalized by Porphyrins and Phthalocyanines for Optoelectronic Properties.

    Science.gov (United States)

    Wang, Aijian; Ye, Jun; Humphrey, Mark G; Zhang, Chi

    2018-04-01

    In recent years, there has been a rapid growth in studies of the optoelectronic properties of graphene, carbon nanotubes (CNTs), and their derivatives. The chemical functionalization of graphene and CNTs is a key requirement for the development of this field, but it remains a significant challenge. The focus here is on recent advances in constructing nanohybrids of graphene or CNTs covalently linked to porphyrins or phthalocyanines, as well as their application in nonlinear optics. Following a summary of the syntheses of nanohybrids constructed from graphene or CNTs and porphyrins or phthalocyanines, explicit intraconjugate electronic interactions between photoexcited porphyrins/phthalocyanines and graphene/CNTs are introduced classified by energy transfer, electron transfer, and charge transfer, and their optoelectronic applications are also highlighted. The major current challenges for the development of covalently linked nanohybrids of porphyrins or phthalocyanines and carbon nanostructures are also presented. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. State-of-the-art photodetectors for optoelectronic integration at telecommunication wavelength

    Directory of Open Access Journals (Sweden)

    Eng Png Ching

    2015-01-01

    Full Text Available Photodetectors hold a critical position in optoelectronic integrated circuits, and they convert light into electricity. Over the past decades, high-performance photodetectors (PDs have been aggressively pursued to enable high-speed, large-bandwidth, and low-noise communication applications. Various material systems have been explored and different structures designed to improve photodetection capability as well as compatibility with CMOS circuits. In this paper, we review state-of-theart photodetection technologies in the telecommunications spectrum based on different material systems, including traditional semiconductors such as InGaAs, Si, Ge and HgCdTe, as well as recently developed systems such as low-dimensional materials (e.g. graphene, carbon nanotube, etc. and noble metal plasmons. The corresponding material properties, fundamental mechanisms, fabrication, theoretical modelling and performance of the typical PDs are presented, including the emerging directions and perspectives of the PDs for optoelectronic integration applications are discussed.

  12. Compensating Unknown Time-Varying Delay in Opto-Electronic Platform Tracking Servo System

    Directory of Open Access Journals (Sweden)

    Ruihong Xie

    2017-05-01

    Full Text Available This paper investigates the problem of compensating miss-distance delay in opto-electronic platform tracking servo system. According to the characteristic of LOS (light-of-sight motion, we setup the Markovian process model and compensate this unknown time-varying delay by feed-forward forecasting controller based on robust H∞ control. Finally, simulation based on double closed-loop PI (Proportion Integration control system indicates that the proposed method is effective for compensating unknown time-varying delay. Tracking experiments on the opto-electronic platform indicate that RMS (root-mean-square error is 1.253 mrad when tracking 10° 0.2 Hz signal.

  13. Effect of methyl substitution on optoelectronic properties of 1,3,6,8-tetraphenyl pyrenes

    Directory of Open Access Journals (Sweden)

    LIU Yanling

    2014-06-01

    Full Text Available Geometric structures of the ground states and excited states,frontier molecular orbitals,ionization potentials,electron affinities,reorganization energies,and absorption and emission spectra of three novel methyl-substituted 1,3,6,8-tetra-phenylpyrenes were studied theoretically by quantum-chemical methods,such as density functional theory (DFT.The results show that the position of methyl substituent on benzene ring has much effect on the optoelectronic properties of methyl-substituted 1,3,6,8-tetra-phenylpyrenes.Interestingly,the geometric structures and optoelectronic properties of the designed compound 1,3,6,8-tetra-p-tolylpyrene (TPPy are similar to those of 1,3,6,8-tetrakis(3,5-dimethylphenylpyrene (TDMPPy,which is worthy of being further researched.

  14. Effect of annealing over optoelectronic properties of graphene based transparent electrodes

    Science.gov (United States)

    Yadav, Shriniwas; Kaur, Inderpreet

    2016-04-01

    Graphene, an atom-thick two dimensional graphitic material have led various fundamental breakthroughs in the field of science and technology. Due to their exceptional optical, physical and electrical properties, graphene based transparent electrodes have shown several applications in organic light emitting diodes, solar cells and thin film transistors. Here, we are presenting effect of annealing over optoelectronic properties of graphene based transparent electrodes. Graphene based transparent electrodes have been prepared by wet chemical approach over glass substrates. After fabrication, these electrodes tested for optical transmittance in visible region. Sheet resistance was measured using four probe method. Effect of thermal annealing at 200 °C was studied over optical and electrical performance of these electrodes. Optoelectronic performance was judged from ratio of direct current conductivity to optical conductivity (σdc/σopt) as a figure of merit for transparent conductors. The fabricated electrodes display good optical and electrical properties. Such electrodes can be alternatives for doped metal oxide based transparent electrodes.

  15. The relationship between past caries experience and tooth color determined by an opto-electronic method.

    Science.gov (United States)

    Kerosuo, E; Kolehmainen, L

    1982-01-01

    The susceptibility of a tooth to dental caries has been proposed to depend on tooth color. So far there has, however, been no reliable method for tooth color determination. The aims of this study were to evaluate the reliability of an opto-electronic method and to examine the relationship between tooth color and past caries experience. The color of upper right central incisors of 64 school-children was determined using an opto-electronic tri-stimulus color comparator. The intra- and interexaminer reliability of the method was evaluated in vitro and in vivo being 85% and 83%, respectively. To assess the past caries experience the DMFS-index was calculated. Oral hygiene and dietary habits were also assessed. No significant difference in DMFS scores was obtained between the 'white teeth' group and the 'yellow teeth' group. The conclusion is, that the practical importance of possible colorrelated differences in caries resistance is negligible due to the multifaceted nature of dental caries.

  16. Optoelectronic and Photovoltaic Properties of the Air-Stable Organohalide Semiconductor (CH 3 NH 3 ) 3 Bi 2 I 9

    KAUST Repository

    Abulikemu, Mutalifu; Ould-Chikh, Samy; Miao, Xiaohe; Alarousu, Erkki; Banavoth, Murali; Ngongang Ndjawa, Guy Olivier; Barbe, Jeremy; El Labban, Abdulrahman; Amassian, Aram; Del Gobbo, Silvano

    2016-01-01

    Lead halide perovskite materials have shown excellent optoelectronic as well as photovoltaic properties. However, the presence of lead and the chemical instability relegate lead halide perovskites to research applications only. Here, we investigate

  17. Design and test of optoelectronic system of alignment control based on CCD camera

    Science.gov (United States)

    Anisimov, A. G.; Gorbachyov, A. A.; Krasnyashchikh, A. V.; Pantushin, A. N.; Timofeev, A. N.

    2008-10-01

    In this work, design, implementation and test of a system intended for positioning of the elements of turbine units relative to the line of shaft with high precision, are discussed. A procedure of the conversion of coordinates from the instrument system into the system connected with the practical position of the axis of turbine has been devised. It is shown that optoelectronic systems of aligment built by autoreflexive scheme can be used for high precision measurements.

  18. OMNI: An optoelectronic multichannel network interface based on hybrid CMOS-SEED technology

    Science.gov (United States)

    Pinkston, Timothy M.

    1996-11-01

    This paper presents a hybrid CMOS-SEED multiprocessor network interface smart pixel design that implements a reservation-based channel control protocol for collisionless concurrent access to multiple optical interprocessor communication channels. An asynchronous optical token is used as the arbitration mechanism for reservation control instead of slotted access. This work demonstrates that complex network protocol functions can be implemented using optoelectronic smart pixel technology.

  19. Direct olefination of fluorinated benzothiadiazoles: a new entry to optoelectronic materials.

    Science.gov (United States)

    Xiao, Yu-Lan; Zhang, Bo; He, Chun-Yang; Zhang, Xingang

    2014-04-14

    Fluorinated olefin-containing benzothiadiazoles have important applications in optoelectronic materials. Herein, we reported the direct olefination of fluorinated benzothiadiazoles, as catalyzed by palladium. The reaction proceeds under mild reaction conditions and shows high functional-group compatibility. A preliminary study of the properties of the resulting symmetrical and unsymmetrical olefin-containing fluorinated benzothiadiazoles in red-light-emitting dyes has also been conducted. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Optoelectronic link for analog signals from solid state detectors in high energy physics

    International Nuclear Information System (INIS)

    Manfredi, P.F.; Speziali, V.

    1983-01-01

    An optoelectric link has been made to transmit analog signals over a long distance between the beam area and the remote-end data acquisition instrumentation in high energy experiments. The optoelectronic link is intended for silicon target applications and it is designed to work on the signals at the output of a low noise amplifier system. Its advantages over a conventional galvanic connection as well as its limitations are discussed. (orig.)

  1. Proceedings of the thirty fifth international conference on contemporary trends in optics and optoelectronics: conference digest - extended abstracts

    International Nuclear Information System (INIS)

    2011-01-01

    Optics and optoelectronics are indispensable in all spheres of human activity, ranging from day to day needs to advanced scientific and technological pursuits and their applications for the benefit of the society. This conference covers the following topics: adaptive optics, biomedical optics and imaging, classical and quantum optics, fibre optics, optics for space applications, optical metrology and NDT, optical information processing, optical and optoelectronic materials. Papers relevant to INIS are indexed separately

  2. Maximizing Tensile Strain in Germanium Nanomembranes for Enhanced Optoelectronic Properties

    Science.gov (United States)

    Sanchez Perez, Jose Roberto

    Silicon, germanium, and their alloys, which provide the leading materials platform of microelectronics, are extremely inefficient light emitters because of their indirect fundamental energy band gap. This basic materials property has so far hindered the development of group-IV photonic-active devices, including light emitters and diode lasers, thereby significantly limiting our ability to integrate electronic and photonic functionalities at the chip level. Theoretical studies have predicted that tensile strain in Ge lowers the direct energy band gap relative to the indirect one, and that, with sufficient strain, Ge becomes direct-band gap, thus enabling facile interband light emission and the fabrication of Group IV lasers. It has, however, not been possible to impart sufficient strain to Ge to reach the direct-band gap goal, because bulk Ge fractures at much lower strains. Here it is shown that very thin sheets of Ge(001), called nanomembranes (NMs), can be used to overcome this materials limitation. Germanium nanomembranes (NMs) in the range of thicknesses from 20nm to 100nm were fabricated and then transferred and mounted to a flexible substrate [a polyimide (PI) sheet]. An apparatus was developed to stress the PI/NM combination and provide for in-situ Raman measurements of the strain as a function of applied stress. This arrangement allowed for the introduction of sufficient biaxial tensile strain (>1.7%) to transform Ge to a direct-band gap material, as determined by photoluminescence (PL) measurements and theory. Appropriate shifts in the emission spectrum and increases in PL intensities were observed. The advance in this work was nanomembrane fabrication technology; i.e., making thin enough Ge sheets to accept sufficiently high levels of strain without fracture. It was of interest to determine if the strain at which fracture ultimately does occur can be raised, by evaluating factors that initiate fracture. Attempts to assess the effect of free edges (enchant

  3. Information, optoelectronics, and information technologies (historic, philosophical, and logical aspects)

    Science.gov (United States)

    Dzhaliashvili, Zurab O.; Suhorukova, Marina V.

    2001-06-01

    this purpose it is necessary to study the process of creating that what is possible to determine as information channels: signal lights (optical transmission mode of the information), radio waves, electrons in the semiconductor-devices, quantum in optic fibers, etc. The technological methods of every possible technical realization of information channels exhibit on this evolution course the obvious order. Since concept 'information' has been recognized as the self-maintained category, it has become clear, that it is necessary to be with it considered, as with requirements of an environment of a habitation. Now basic way of administration of any processes in community is the management of information streams.

  4. Noninvasive Optoelectronic Assessment of Induced Sagittal Imbalance Using the Vicon System.

    Science.gov (United States)

    Ould-Slimane, Mourad; Latrobe, Charles; Michelin, Paul; Chastan, Nathalie; Dujardin, Franck; Roussignol, Xavier; Gauthé, Rémi

    2017-06-01

    Spinal diseases often induce gait disorders with multifactorial origins such as lumbar pain, radicular pain, neurologic complications, or spinal deformities. However, radiography does not permit an analysis of spinal dynamics; therefore, sagittal balance dynamics during gait remain largely unexplored. This prospective and controlled pilot study assessed the Vicon system for detecting sagittal spinopelvic imbalance, to determine the correlations between optoelectronic and radiographic parameters. Reversible anterior sagittal imbalance was induced in 24 healthy men using a thoracolumbar corset. Radiographic, optoelectronic, and comparative analyses were conducted. Corset wearing induced significant variations in radiographic parameters indicative of imbalance; the mean C7-tilt and d/D ratio increased by 15° ± 7.4° and 359%, respectively, whereas the mean spinosacral angle decreased by 16.8° ± 8° (all P imbalance; the mean spinal angle increased by 15.4° ± 5.6° (P imbalance detected using the Vicon system. Optoelectronic C7'S1' correlated with radiographic C7-tilt and d/D ratio. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Optical and Optoelectronic Property Analysis of Nanomaterials inside Transmission Electron Microscope.

    Science.gov (United States)

    Fernando, Joseph F S; Zhang, Chao; Firestein, Konstantin L; Golberg, Dmitri

    2017-12-01

    In situ transmission electron microscopy (TEM) allows one to investigate nanostructures at high spatial resolution in response to external stimuli, such as heat, electrical current, mechanical force and light. This review exclusively focuses on the optical, optoelectronic and photocatalytic studies inside TEM. With the development of TEMs and specialized TEM holders that include in situ illumination and light collection optics, it is possible to perform optical spectroscopies and diverse optoelectronic experiments inside TEM with simultaneous high resolution imaging of nanostructures. Optical TEM holders combining the capability of a scanning tunneling microscopy probe have enabled nanomaterial bending/stretching and electrical measurements in tandem with illumination. Hence, deep insights into the optoelectronic property versus true structure and its dynamics could be established at the nanometer-range precision thus evaluating the suitability of a nanostructure for advanced light driven technologies. This report highlights systems for in situ illumination of TEM samples and recent research work based on the relevant methods, including nanomaterial cathodoluminescence, photoluminescence, photocatalysis, photodeposition, photoconductivity and piezophototronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Filterless low-phase-noise frequency-quadrupled microwave generation based on a multimode optoelectronic oscillator

    Science.gov (United States)

    Teng, Yichao; Zhang, Pin; Zhang, Baofu; Chen, Yiwang

    2018-02-01

    A scheme to realize low-phase-noise frequency-quadrupled microwave generation without any filter is demonstrated. In this scheme, a multimode optoelectronic oscillator is mainly contributed by dual-parallel Mach-Zehnder modulators, fiber, photodetector, and microwave amplifier. The local source signal is modulated by a child MZM (MZMa), which is worked at maximum transmission point. Through properly adjusting the bias voltages of the other child MZM (MZMb) and the parent MZM (MZMc), optical carrier is effectively suppressed and second sidebands are retained, then the survived optical signal is fed back to the photodetector and MZMb to form an optoelectronic hybrid resonator and realize frequency-quadrupled signal generation. Due to the high Q-factor and mode selection effect of the optoelectronic hybrid resonator, compared with the source signal, the generated frequency-quadrupled signal has a lower phase noise. The approach has verified by experiments, and 18, 22, and 26 GHz frequency-quadrupled signal are generated by 4.5, 5.5, and 6.5 GHz local source signals. Compared with 4.5 GHz source signal, the phase noise of generated 18 GHz signal at 10 kHz frequency offset has 26.5 dB reduction.

  7. Cultivation of students' engineering designing ability based on optoelectronic system course project

    Science.gov (United States)

    Cao, Danhua; Wu, Yubin; Li, Jingping

    2017-08-01

    We carry out teaching based on optoelectronic related course group, aiming at junior students majored in Optoelectronic Information Science and Engineering. " Optoelectronic System Course Project " is product-designing-oriented and lasts for a whole semester. It provides a chance for students to experience the whole process of product designing, and improve their abilities to search literature, proof schemes, design and implement their schemes. In teaching process, each project topic is carefully selected and repeatedly refined to guarantee the projects with the knowledge integrity, engineering meanings and enjoyment. Moreover, we set up a top team with professional and experienced teachers, and build up learning community. Meanwhile, the communication between students and teachers as well as the interaction among students are taken seriously in order to improve their team-work ability and communicational skills. Therefore, students are not only able to have a chance to review the knowledge hierarchy of optics, electronics, and computer sciences, but also are able to improve their engineering mindset and innovation consciousness.

  8. Field-Programmable Logic Devices with Optical Input Output

    Science.gov (United States)

    Szymanski, Ted H.; Saint-Laurent, Martin; Tyan, Victor; Au, Albert; Supmonchai, Boonchuay

    2000-02-01

    A field-programmable logic device (FPLD) with optical I O is described. FPLD s with optical I O can have their functionality specified in the field by means of downloading a control-bit stream and can be used in a wide range of applications, such as optical signal processing, optical image processing, and optical interconnects. Our device implements six state-of-the-art dynamically programmable logic arrays (PLA s) on a 2 mm 2 mm die. The devices were fabricated through the Lucent Technologies Advanced Research Projects Agency Consortium for Optical and Optoelectronic Technologies in Computing (Lucent ARPA COOP) workshop by use of 0.5- m complementary metal-oxide semiconductor self-electro-optic device technology and were delivered in 1998. All devices are fully functional: The electronic data paths have been verified at 200 MHz, and optical tests are pending. The device has been programmed to implement a two-stage optical switching network with six 4 4 crossbar switches, which can realize more than 190 10 6 unique programmable input output permutations. The same device scaled to a 2 cm 2 cm substrate could support as many as 4000 optical I O and 1 Tbit s of optical I O bandwidth and offer fully programmable digital functionality with approximately 110,000 programmable logic gates. The proposed optoelectronic FPLD is also ideally suited to realizing dense, statically reconfigurable crossbar switches. We describe an attractive application area for such devices: a rearrangeable three-stage optical switch for a wide-area-network backbone, switching 1000 traffic streams at the OC-48 data rate and supporting several terabits of traffic.

  9. Guide device

    International Nuclear Information System (INIS)

    Brammer, C.M. Jr.

    1977-01-01

    Disclosed is a fuel handling guide tube centering device for use in nuclear reactors during fuel assembly handling operations. The device comprises an outer ring secured to the flange of a nuclear reactor pressure vessel, a rotatable table rotatably coupled to the outer ring, and a plurality of openings through the table. Truncated locating cones are positioned in each of the openings in the table, and the locating cones center the guide tube during fuel handling operations. The openings in the table are located such that each fuel assembly in the nuclear core may be aligned with one of the openings by a suitable rotation of the table. The locating cones thereby provide alignment between the fuel handling mechanism located in the guide tube and the individual fuel assemblies of the cone. The need for a device to provide alignment is especially critical for floating nuclear power plants, where wave motion may exist during fuel handling operations. 5 claims, 4 figures

  10. Polarity in GaN and ZnO: Theory, measurement, growth, and devices

    Science.gov (United States)

    Zúñiga-Pérez, Jesús; Consonni, Vincent; Lymperakis, Liverios; Kong, Xiang; Trampert, Achim; Fernández-Garrido, Sergio; Brandt, Oliver; Renevier, Hubert; Keller, Stacia; Hestroffer, Karine; Wagner, Markus R.; Reparaz, Juan Sebastián; Akyol, Fatih; Rajan, Siddharth; Rennesson, Stéphanie; Palacios, Tomás; Feuillet, Guy

    2016-12-01

    The polar nature of the wurtzite crystalline structure of GaN and ZnO results in the existence of a spontaneous electric polarization within these materials and their associated alloys (Ga,Al,In)N and (Zn,Mg,Cd)O. The polarity has also important consequences on the stability of the different crystallographic surfaces, and this becomes especially important when considering epitaxial growth. Furthermore, the internal polarization fields may adversely affect the properties of optoelectronic devices but is also used as a potential advantage for advanced electronic devices. In this article, polarity-related issues in GaN and ZnO are reviewed, going from theoretical considerations to electronic and optoelectronic devices, through thin film, and nanostructure growth. The necessary theoretical background is first introduced and the stability of the cation and anion polarity surfaces is discussed. For assessing the polarity, one has to make use of specific characterization methods, which are described in detail. Subsequently, the nucleation and growth mechanisms of thin films and nanostructures, including nanowires, are presented, reviewing the specific growth conditions that allow controlling the polarity of such objects. Eventually, the demonstrated and/or expected effects of polarity on the properties and performances of optoelectronic and electronic devices are reported. The present review is intended to yield an in-depth view of some of the hot topics related to polarity in GaN and ZnO, a fast growing subject over the last decade.

  11. Synthesis and Characterization of Novel Transition Metal Chalcogenide Phases for Energy Storage, Energy Conversion and Optoelectronics

    Science.gov (United States)

    Chen, Erica Maxine

    -film fabrication. Chapter 5 describes a brief study in utilizing elemental substitution in Cu4TiSe4 to alter the band gap by replacing sulfur into the selenium site. In this study, the amount of selenium which may be substituted without deviating from the parent Cu4TiSe4 structure is 16 % at and the direct band gap is alterable from 1.34 eV to 1.64 eV as determined from conducting tauc analysis on the diffuse reflectance spectra. The last experimental work in Chapter 6 covers the development of a chemical substitution series between the end compounds Cu3NbS 4 and Cu3NbSe4. Through powdered x-ray diffraction of the series, it was found that for substituting less than 25% of the sulfur with selenium, the powdered patterns more closely resembled Cu3NbS 4 and with shift which may see further development and application in optoelectronic devices such as LEDs. Finally, Chapter 7 provides further guidance in the research which this thesis may serve as a springboard for the development of ultra-high efficiency, low-cost, environmentally friendly and thin photovoltaics as well as mention other characterization methods which are necessary to diagnose and elucidate complications.

  12. Tuning optoelectronic properties of small semiconductor nanocrystals through surface ligand chemistry

    Science.gov (United States)

    Lawrence, Katie N.

    Semiconductor nanocrystals (SNCs) are a class of material with one dimension wave function 1) into the ligand monolayer using metal carboxylates and 2) beyond the ligand monolayer to provide strong inter-SNC electronic coupling using poly(ethylene) glycol (PEG)-thiolate was explored. Passivation of the Se sites of metal chalcogenide SNCs by metal carboxylates provided a two-fold outcome: (1) facilitating the delocalization of exciton wave functions into ligand monolayers (through appropriate symmetry matching and energy alignment) and (2) increasing fluorescence quantum yield (through passivation of midgap trap states). An ˜240 meV red-shift in absorbance was observed upon addition of Cd(O2CPh)2, as well as a ˜260 meV shift in emission with an increase in PL-QY to 73%. Through a series of control experiments, as well as full reversibility of our system, we were able to conclude that the observed bathochromic shifts were the sole consequence of delocalization, not a change in size or relaxation of the inorganic core, as previously reported. Furthermore, the outstanding increase in PL-QY was found to be a product of both passivation and delocalization effects. Next we used poly(ethylene) glycol (PEG)-thiolate ligands to passivate the SNC and provide unique solubility properties in both aqueous and organic solvents as well as utilized their highly conductive nature to explore inter-SNC electronic coupling. The electronic coupling was studied: 1) as a function of SNC size where the smallest SNC exhibited the largest coupling energy (170 meV) and 2) as a function of annealing temperature, where an exceptionally large (˜400 meV) coupling energy was observed. This strong electronic coupling in self-organized films could facilitate the large-scale production of highly efficient electronic materials for advanced optoelectronic device applications. Strong inter-SNC electronic coupling together with high solubility, such as that provided by PEG-thiolate-coated CdSe SNCs

  13. Mechanical properties of amorphous indium–gallium–zinc oxide thin films on compliant substrates for flexible optoelectronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed, D.W., E-mail: DWM172@bham.ac.uk [University of Birmingham, School of Metallurgy and Materials, Edgbaston, Birmingham, B15 2TT (United Kingdom); Waddingham, R.; Flewitt, A.J. [University of Cambridge, Electrical Engineering Division, Department of Engineering, J J Thomson Avenue, Cambridge CB3 0FA,United Kingdom (United Kingdom); Sierros, K.A. [West Virginia University, Mechanical & Aerospace Engineering, Morgantown, WV 26506 (United States); Bowen, J. [Open University, Department of Engineering and Innovation, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Kukureka, S.N. [University of Birmingham, School of Metallurgy and Materials, Edgbaston, Birmingham, B15 2TT (United Kingdom)

    2015-11-02

    Amorphous indium–gallium–zinc-oxide (a-IGZO) thin films were deposited using RF magnetron sputtering on polyethylene naphthalate (PEN) and polyethylene terephthalate (PET) flexible substrates and their mechanical flexibility investigated using uniaxial tensile and buckling tests coupled with in situ optical microscopy. The uniaxial fragmentation test demonstrated that the crack onset strain of the IGZO/PEN was ~ 2.9%, which is slightly higher than that of IGZO/PET. Also, uniaxial tensile crack density analysis suggests that the saturated crack spacing of the film is strongly dependent on the mechanical properties of the underlying polymer substrate. Buckling test results suggest that the crack onset strain (equal to ~ 1.2%, of the IGZO/polymer samples flexed in compression to ~ 5.7 mm concave radius of curvature) is higher than that of the samples flexed with the film being in tension (convex bending) regardless whether the substrate is PEN or PET. The saturated crack density of a-IGZO film under the compression buckling mode is smaller than that of the film under the tensile buckling mode. This could be attributed to the fact that the tensile stress encouraged this crack formation originating from surface defects in the coating. It could also be due to the buckling delamination of the thin coating from the substrate at a lower strain than that at which a crack initiates during flexing in compression. These results provide useful information on the mechanical reliability of a-IGZO films for the development of flexible electronics. - Highlights: • Mechanical flexibility of IGZO thin films investigated by uniaxial tensile and buckling tests • Uniaxial fragmentation gives crack onset strain for IGZO/PEN of 2.9% (higher than for IGZO/PET.) • Saturated crack spacing strongly dependent on mechanical properties of polymer substrate • Crack onset strain in concave bending higher than in convex bending for both substrates.

  14. Mechanical properties of amorphous indium–gallium–zinc oxide thin films on compliant substrates for flexible optoelectronic devices

    International Nuclear Information System (INIS)

    Mohammed, D.W.; Waddingham, R.; Flewitt, A.J.; Sierros, K.A.; Bowen, J.; Kukureka, S.N.

    2015-01-01

    Amorphous indium–gallium–zinc-oxide (a-IGZO) thin films were deposited using RF magnetron sputtering on polyethylene naphthalate (PEN) and polyethylene terephthalate (PET) flexible substrates and their mechanical flexibility investigated using uniaxial tensile and buckling tests coupled with in situ optical microscopy. The uniaxial fragmentation test demonstrated that the crack onset strain of the IGZO/PEN was ~ 2.9%, which is slightly higher than that of IGZO/PET. Also, uniaxial tensile crack density analysis suggests that the saturated crack spacing of the film is strongly dependent on the mechanical properties of the underlying polymer substrate. Buckling test results suggest that the crack onset strain (equal to ~ 1.2%, of the IGZO/polymer samples flexed in compression to ~ 5.7 mm concave radius of curvature) is higher than that of the samples flexed with the film being in tension (convex bending) regardless whether the substrate is PEN or PET. The saturated crack density of a-IGZO film under the compression buckling mode is smaller than that of the film under the tensile buckling mode. This could be attributed to the fact that the tensile stress encouraged this crack formation originating from surface defects in the coating. It could also be due to the buckling delamination of the thin coating from the substrate at a lower strain than that at which a crack initiates during flexing in compression. These results provide useful information on the mechanical reliability of a-IGZO films for the development of flexible electronics. - Highlights: • Mechanical flexibility of IGZO thin films investigated by uniaxial tensile and buckling tests • Uniaxial fragmentation gives crack onset strain for IGZO/PEN of 2.9% (higher than for IGZO/PET.) • Saturated crack spacing strongly dependent on mechanical properties of polymer substrate • Crack onset strain in concave bending higher than in convex bending for both substrates

  15. 2-Amino 4-methylpyridinium 3-chlorobenzoate - A phase matchable organic nonlinear optical material for optoelectronics device applications

    Science.gov (United States)

    Babu, B.; Chandrasekaran, J.; Thirumurugan, R.; Anitha, K.; Saravanabhavan, M.

    2017-09-01

    2-Amino 4-methylpyridinium 3-chlorobenzoate (2A4M3CB) was synthesized and good quality single crystals of the size of 8 × 2 × 1.2 mm3 were harvested from methanol by the slow evaporation solution growth technique at ambient temperature. Single crystal XRD reveals that 2A4M3CB crystallized in monoclinic system with the noncentrosymmetric space group P21. The crystalline phases and functional groups of 2A4M3CB have been identified and confirmed through powder X-ray diffraction and Fourier transform infrared (FTIR) studies, respectively. 1H and 13C NMR were recorded to interpret the molecular structure. The optical transmittance window and the lower cutoff wavelength of the 2A4M3CB have been identified by UV-Vis-NIR studies. Thermal and mechanical stability of the 2A4M3CB crystals were explained by TG/DTA and Vickers hardness analysis. Charge transport mechanism and photo response properties were analyzed through dielectric and photoconductivity studies. Powder second harmonic generation (SHG) characteristics and phase matching ability were explored by Kurtz and Perry powder SHG technique.

  16. Oxidation of GaAs substrates to enable β-Ga2O3 films for sensors and optoelectronic devices

    Science.gov (United States)

    Mao, Howard; Alhalaili, Badriyah; Kaya, Ahmet; Dryden, Daniel M.; Woodall, Jerry M.; Islam, M. Saif

    2017-08-01

    A very simple and inexpensive method for growing β-Ga2O3 films by heating GaAs wafers at high temperature in a furnace was found to contribute to large-area, high-quality β-Ga2O3 nanoscale thin films as well as nanowires depending on the growth conditions. We present the material characterization results including the optical band gap, Schottky barrier height with metal (gold), field ionization and photoconductance of β-Ga2O3 film and nanowires.

  17. Applications of Robust, Radiation Hard AlGaN Optoelectronic Devices in Space Exploration and High Energy Density Physics

    Energy Technology Data Exchange (ETDEWEB)

    Sun, K.

    2011-05-04

    This slide show presents: space exploration applications; high energy density physics applications; UV LED and photodiode radiation hardness; UV LED and photodiode space qualification; UV LED AC charge management; and UV LED satellite payload instruments. A UV LED satellite will be launched 2nd half 2012.

  18. Growth and characterizaion of urea p-nitrophenol crystal: an organic nonlinear optical material for optoelectronic device application

    Science.gov (United States)

    Suresh, A.; Manikandan, N.; Jauhar, RO. MU.; Murugakoothan, P.; Vinitha, G.

    2018-06-01

    Urea p-nitrophenol, an organic nonlinear optical crystal was synthesized and grown adopting slow evaporation and seed rotation method. Single crystal X-ray diffraction study confirmed the formation of the desired crystal. High resolution X-ray diffraction study showed the defect nature of the crystal. The presence of functional groups in the material was confirmed by FTIR analysis. UV-Vis-NIR study indicates that the grown crystal has a wider transparency region with the lower cutoff wavelength at 423 nm. The grown crystal is thermally stable up to 120 °C as assessed by TG-DTA analysis. The optical homogeneity of the grown crystal was confirmed by birefringence study. The 1064 nm Nd-YAG laser was used to obtain laser induced surface damage threshold which was found to be 0.38, 0.25 and 0.33 GW/cm2 for (0 1 0), (1 1 - 1) and (0 1 1) planes, respectively. The dielectric study was performed to find the charge distribution inside the crystal. The hardness property of the titular material has been found using Vicker's microhardness study. The optical nonlinearity obtained from third order nonlinear optical measurements carried out using Z-scan technique showed that these samples could be exploited for optical limiting studies.

  19. Medical Devices

    NARCIS (Netherlands)

    Verkerke, Gijsbertus Jacob; Mahieu, H.F.; Geertsema, A.A.; Hermann, I.F.; van Horn, J.R.; Hummel, J. Marjan; van Loon, J.P.; Mihaylov, D.; van der Plaats, A.; Schraffordt Koops, H.; Schutte, H.K.; Veth, R.P.H.; de Vries, M.P.; Rakhorst, G.; Shi, Donglu

    2004-01-01

    The development of new medical devices is a very time-consuming and costly process. Besides the time between the initial idea and the time that manufacturing and testing of prototypes takes place, the time needed for the development of production facilities, production of test series, marketing,

  20. Electrochemical device

    Science.gov (United States)

    Grimes, Patrick G.; Einstein, Harry; Bellows, Richard J.

    1988-01-12

    A tunnel protected electrochemical device features channels fluidically communicating between manifold, tunnels and cells. The channels are designed to provide the most efficient use of auxiliary power. The channels have a greater hydraulic pressure drop and electrical resistance than the manifold. This will provide a design with the optimum auxiliary energy requirements.