WorldWideScience

Sample records for arsenide junction-field-effect transistors

  1. Radiation dosimetry using junction field-effect transistor detectors

    International Nuclear Information System (INIS)

    The use of junction field effect transistors (JFET) has been studied by connecting them in a bridge circuit. With a suitable back-up circuit, it was possible to measure doses as well as dose-rates. It was possible to alter the sensitivity of the JFET bridge by varying the biasing components of the JFET. Easy temperature compensation was also possible. However, response of the JFET to radiation showed energy dependency similar to that of semiconductor diodes. (author)

  2. Field emission current from a junction field-effect transistor

    International Nuclear Information System (INIS)

    Fabrication of a titanium dioxide/carbon nanotube (TiO2/CNT)-based transistor is reported. The transistor can be considered as a combination of a field emission transistor and a junction field-effect transistor. Using direct current plasma-enhanced chemical vapor deposition (DC-PECVD) technique, CNTs were grown on a p-typed (100)-oriented silicon substrate. The CNTs were then covered by TiO2 nanoparticles 2–5 nm in size, using an atmospheric pressure CVD technique. In this device, TiO2/CNT junction is responsible for controlling the emission current. High on/off-current ratio and proper gate control are the most important advantages of device. A model based on Fowler–Nordheim equation is utilized for calculation of the emission current and the results are compared with experimental data. The effect of TiO2/CNT hetero-structure is also investigated, and well modeled

  3. Field emission current from a junction field-effect transistor

    Energy Technology Data Exchange (ETDEWEB)

    Monshipouri, Mahta; Abdi, Yaser, E-mail: y.abdi@ut.ac.ir [University of Tehran, Nano-Physics Research Laboratory, Department of Physics (Iran, Islamic Republic of)

    2015-04-15

    Fabrication of a titanium dioxide/carbon nanotube (TiO{sub 2}/CNT)-based transistor is reported. The transistor can be considered as a combination of a field emission transistor and a junction field-effect transistor. Using direct current plasma-enhanced chemical vapor deposition (DC-PECVD) technique, CNTs were grown on a p-typed (100)-oriented silicon substrate. The CNTs were then covered by TiO{sub 2} nanoparticles 2–5 nm in size, using an atmospheric pressure CVD technique. In this device, TiO{sub 2}/CNT junction is responsible for controlling the emission current. High on/off-current ratio and proper gate control are the most important advantages of device. A model based on Fowler–Nordheim equation is utilized for calculation of the emission current and the results are compared with experimental data. The effect of TiO{sub 2}/CNT hetero-structure is also investigated, and well modeled.

  4. Monolithic junction field-effect transistor charge preamplifier for calorimetry at high luminosity hadron colliders

    International Nuclear Information System (INIS)

    The outstanding noise and radiation hardness characteristics of epitaxial-channel junction field-effect transistors (JFET) suggest that a monolithic preamplifier based upon them may be able to meet the strict specifications for calorimetry at high luminosity colliders. Results obtained so far with a buried layer planar technology, among them an entire monolithic charge-sensitive preamplifier, are described

  5. A novel 10-nm physical gate length double-gate junction field effect transistor

    Institute of Scientific and Technical Information of China (English)

    Hou Xiao-Yu; Huang Ru; Chen Gang; Liu Sheng; Zhang Xing; Yu Bin; Wang Yang-Yuan

    2008-01-01

    A novel double-gate (DG) junction field effect transistor (JFET) with depletion operation mode is proposed in this paper.Compared with the conventional DG MOSFET,the novel DG JFET can achieve excellent performance with square body design,which relaxes the requirement on silicon film thickness of DG devices.Moreover,due to the structural symmetry,both p-type and n-type devices can be realized on exactly the same structure,which greatly simplifies integration.It can reduce the delay by about 60% in comparison with the conventional DG MOSFETs.

  6. A new model for four-terminal junction field-effect transistors

    Science.gov (United States)

    Ding, Hao; Liou, Juin J.; Green, Keith; Cirba, Claude R.

    2006-03-01

    This paper presents a compact and semi-empirical model for a four-terminal (independent top and bottom gates) junction field-effect transistor (JFET). The model describes the steady-state characteristics for all bias conditions with a unified equation. Moreover, the model provides a high degree of accuracy and continuity for the different operation regions, a critical factor for robust analog circuit simulations. Capacitance modeling is also included to describe the JFET small-signal behavior. The model has been implemented in Cadence framework via Verilog-A and compared with data measured from JFETs used at Texas Instruments.

  7. Gallium nitride junction field effect transistors for high-temperature operation

    Energy Technology Data Exchange (ETDEWEB)

    Zolper, J.C.; Shul, R.J.; Baca, A.G.; Hietala, V.M. [Sandia National Labs., Albuquerque, NM (United States); Pearton, S.J. [Univ. of Florida, Gainesville, FL (United States). Dept. of Materials Science and Engineering; Stall, R.A. [Emcore Corp., Somerset, NJ (United States); Wilson, R.G. [Hughes Research Labs., Malibu, CA (United States)

    1996-06-01

    GaN is an attractive material for use in high-temperature or high-power electronic devices due to its high bandgap (3.39 eV), high breakdown field ({approximately}5 {times} 10{sup 6} V/cm), high saturation drift velocity (2.7 {times} 10{sup 7} cm/s), and chemical inertness. To this end, Metal Semiconductor FETs (MESFETs), High Electron Mobility Transistors (HEMTs), Heterostructure FETs (HFETs), and Metal Insulator Semiconductor FETs (MISFETs) have all been reported based on epitaxial AlN/GaN structures (Khan 1993a,b; Binari 1994 and 1995). GaN Junction Field Effect Transistors (JFETs), however, had not been reported until recently (Zolper 1996b). JFETs are attractive for high-temperature operation due to the inherently higher thermal stability of the p/n junction gate of a JFET as compared to the Schottky barrier gate of a MESFET or HFET. In this paper the authors present the first results for elevated temperature performance of a GaN JFET. Although the forward gate properties are well behaved at higher temperatures, the reverse characteristics show increased leakage at elevated temperature. However, the increased date leakage alone does not explain the observed increase in drain current with temperature. Therefore, they believe this first device is limited by temperature activated substrate conduction.

  8. Low-Frequency Noise Characterization of Ultra-shallow Gate N-channel Junction Field Effect Transistors

    NARCIS (Netherlands)

    Piccolo, G.; Sarubbi, F.; Vandamme, L.J.K.; Macucci, M.; Scholtes, T.L.M.; Nanver, L.K.

    2007-01-01

    A recently developed technique for ultra shallow pn junction formation has been applied for the fabrication of ring-gate n-channel junction field effect devices (JFET) devices. Several different geometries, gate formation parameters and channel doping profiles have been realized and characterized wi

  9. Characterization, Modeling and Design Parameters Identification of Silicon Carbide Junction Field Effect Transistor for Temperature Sensor Applications

    Directory of Open Access Journals (Sweden)

    Sofiane Khachroumi

    2010-01-01

    Full Text Available Sensor technology is moving towards wide-band-gap semiconductors providing high temperature capable devices. Indeed, the higher thermal conductivity of silicon carbide, (three times more than silicon, permits better heat dissipation and allows better cooling and temperature management. Though many temperature sensors have already been published, little endeavours have been invested in the study of silicon carbide junction field effect devices (SiC-JFET as a temperature sensor. SiC-JFETs devices are now mature enough and it is close to be commercialized. The use of its specific properties versus temperatures is the major focus of this paper. The SiC-JFETs output current-voltage characteristics are characterized at different temperatures. The saturation current and its on-resistance versus temperature are successfully extracted. It is demonstrated that these parameters are proportional to the absolute temperature. A physics-based model is also presented. Relationships between on-resistance and saturation current versus temperature are introduced. A comparative study between experimental data and simulation results is conducted. Important to note, the proposed model and the experimental results reflect a successful agreement as far as a temperature sensor is concerned.

  10. Characterization of vertical GaN p-n diodes and junction field-effect transistors on bulk GaN down to cryogenic temperatures

    Science.gov (United States)

    Kizilyalli, I. C.; Aktas, O.

    2015-12-01

    There is great interest in wide-bandgap semiconductor devices and most recently in vertical GaN structures for power electronic applications such as power supplies, solar inverters and motor drives. In this paper the temperature-dependent electrical behavior of vertical GaN p-n diodes and vertical junction field-effect transistors fabricated on bulk GaN substrates of low defect density (104 to 106 cm-2) is described. Homoepitaxial MOCVD growth of GaN on its native substrate and the ability to control the doping in the drift layers in GaN have allowed the realization of vertical device architectures with drift layer thicknesses of 6 to 40 μm and net carrier electron concentrations as low as 1 × 1015 cm-3. This parameter range is suitable for applications requiring breakdown voltages of 1.2 kV to 5 kV. Mg, which is used as a p-type dopant in GaN, is a relatively deep acceptor (E A ≈ 0.18 eV) and susceptible to freeze-out at temperatures below 200 K. The loss of holes in p-GaN has a deleterious effect on p-n junction behavior, p-GaN contacts and channel control in junction field-effect transistors at temperatures below 200 K. Impact ionization-based avalanche breakdown (BV > 1200 V) in GaN p-n junctions is characterized between 77 K and 423 K for the first time. At higher temperatures the p-n junction breakdown voltage improves due to increased phonon scattering. A positive temperature coefficient in the breakdown voltage is demonstrated down to 77 K; however, the device breakdown characteristics are not as abrupt at temperatures below 200 K. On the other hand, contact resistance to p-GaN is reduced dramatically above room temperature, improving the overall device performance in GaN p-n diodes in all cases except where the n-type drift region resistance dominates the total forward resistance. In this case, the electron mobility can be deconvolved and is found to decrease with T -3/2, consistent with a phonon scattering model. Also, normally-on vertical junction

  11. Characterization of vertical GaN p–n diodes and junction field-effect transistors on bulk GaN down to cryogenic temperatures

    International Nuclear Information System (INIS)

    There is great interest in wide-bandgap semiconductor devices and most recently in vertical GaN structures for power electronic applications such as power supplies, solar inverters and motor drives. In this paper the temperature-dependent electrical behavior of vertical GaN p–n diodes and vertical junction field-effect transistors fabricated on bulk GaN substrates of low defect density (104 to 106 cm−2) is described. Homoepitaxial MOCVD growth of GaN on its native substrate and the ability to control the doping in the drift layers in GaN have allowed the realization of vertical device architectures with drift layer thicknesses of 6 to 40 μm and net carrier electron concentrations as low as 1 × 1015 cm−3. This parameter range is suitable for applications requiring breakdown voltages of 1.2 kV to 5 kV. Mg, which is used as a p-type dopant in GaN, is a relatively deep acceptor (E A ≈ 0.18 eV) and susceptible to freeze-out at temperatures below 200 K. The loss of holes in p-GaN has a deleterious effect on p–n junction behavior, p-GaN contacts and channel control in junction field-effect transistors at temperatures below 200 K. Impact ionization-based avalanche breakdown (BV > 1200 V) in GaN p–n junctions is characterized between 77 K and 423 K for the first time. At higher temperatures the p–n junction breakdown voltage improves due to increased phonon scattering. A positive temperature coefficient in the breakdown voltage is demonstrated down to 77 K; however, the device breakdown characteristics are not as abrupt at temperatures below 200 K. On the other hand, contact resistance to p-GaN is reduced dramatically above room temperature, improving the overall device performance in GaN p–n diodes in all cases except where the n-type drift region resistance dominates the total forward resistance. In this case, the electron mobility can be deconvolved and is found to decrease with T −3/2, consistent with a phonon scattering model. Also, normally

  12. Indium arsenide nanowire field-effect transistors for pH and biological sensing

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, S.; Krogstrup, P.; Nygård, J., E-mail: nygard@nbi.dk [Center for Quantum Devices and Nanoscience Center, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen (Denmark); Frederiksen, R.; Lloret, N.; Martinez, K. L. [Bio-Nanotechnology and Nanomedicine Laboratory, Department of Chemistry and Nanoscience Center, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen (Denmark); De Vico, L.; Jensen, J. H. [Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen (Denmark)

    2014-05-19

    Indium Arsenide is a high mobility semiconductor with a surface electron accumulation layer that allows ohmic electrical contact to metals. Here, we present nanowire devices based on this material as a platform for chemical and biological sensing. The sensing principle involves the binding of a charged species at the sensor surface transduced via field effect into a change in current flowing through the sensor. We show the sensitivity of the platform to the H{sup +} ion concentration in solution as proof of principle and demonstrate the sensitivity to larger charged protein species. The sensors are highly reproducible and reach a detection limit of 10 pM for Avidin.

  13. Low-noise gallium-arsenide field-effect transistor preamplifiers for stochastic beam cooling systems

    International Nuclear Information System (INIS)

    The present noise performance, bandwidth capability and gain stability of bipolar and field-effect transistors, parametric amplifier, Schottky diode mixer and maser are summarized and compared in the 100 MHz to 40 GHz frequency range for stochastic beam cooling systems. Stability factor of GaAs FET's as a function of ambient temperature is presented and discussed. Performance data of several low-noise wide-band cryogenically cooled preamplifiers are presented including one with a noise figure of 0.35 dB over a bandwidth range of 150500 MHz operating at ambient temperature of 200K. Also, data are given on a broadband 1-2 GHz preamplifier having a noise figure of approximately 0.2 dB. The gain, operating noise temperature, stability, gain nonuniformity and phase-shift as function of frequency of interest for beam cooling systems are discussed

  14. Hot-Electron Degradation of Gallium Arsenide Metal-Semiconductor Field-Effect Transistors.

    Science.gov (United States)

    Tkachenko, Yevgeniy A.

    1995-01-01

    The physical mechanism of gradual degradation of GaAs MESFETs during RF overdrive is investigated in detail. A hot-electron effect was found responsible for this so-called "power slump" problem. Hot electrons produced by a large drain-gate voltage swing, tunnel from the MESFET channel and get trapped in SiN. These trapped electrons (i) increase surface depletion, hence reduce maximum channel current, transconductance and transistor gain, (ii) increase knee voltage through an increase in series channel resistance, (iii) relax gate-drain field distribution, thereby suppressing avalanche breakdown, (iv) decrease gate-drain capacitance, hence rm S_{22} under open-channel condition, and (v) increase surface leakage through trap hopping in SiN. The damage to SiN can only be partially recovered by deep UV illumination or 200^circrm C anneal. The evidence supports that trapping occurs in the bulk SiN, instead of at the GaAs/SiN interface. The possible chemical reaction responsible for this trap formation is breaking of the Si-H bond in SiN. An analytical theory of hot-electron effects, which combines hot-electron trapping with gate-drain breakdown and pinched-channel electro-luminescence, was developed and verified using experimental data and numerical simulations. Based on this theory, the rate of hot electron trapping was obtained and the threshold energy for trap formation was determined. The square-root time dependence given by the theory and the threshold energy of 1.9 eV were found consistent with gate current and electro-luminescence measurements. Numerical analysis was consistent with a trap density of the order of 5times10^{12}/rm cm^2 over a distance of approximately 0.1 murm m from the gate toward the drain, and it predicted the experimentally observed open-channel current reduction and gate-drain field relaxation. The spatial distribution of trapped electrons was directly observed by a novel high-voltage electron-beam-induced -current imaging technique. It

  15. Silicon Carbide Junction Field Effect Transistor Digital Logic Gates Demonstrated at 600 deg. C

    Science.gov (United States)

    Neudeck, Philip G.

    1998-01-01

    The High Temperature Integrated Electronics and Sensors (HTIES) Program at the NASA Lewis Research Center is currently developing silicon carbide (SiC) for use in harsh conditions where silicon, the semiconductor used in nearly all of today's electronics, cannot function. The HTIES team recently fabricated and demonstrated the first semiconductor digital logic gates ever to function at 600 C.

  16. Low-noise gallium-arsenide field-effect transistor preamplifiers for stochastic beam-cooling systems

    International Nuclear Information System (INIS)

    The present noise performance, bandwidth capability and gain stability of bipolar and field-effect transistors, parametric amplifier, Schottky diode mixer and maser are summarized and compared in the 100 MHz to 40 GHz frequency range for stochastic beam cooling systems. Stability factor of GaAs FET's as a function of ambient temperature is presented and discussed. Performance data of several low-noise wide-band cryogenically cooled preamplifiers are presented including one with a noise figure of 0.35 dB over a bandwidth range of 150 to 500 MHz operating at ambient temperature of 200K. Also, data are given on a broadband 1 to 2 GHz preamplifier having a noise figure of approximately 0.2 dB. The gain, operating noise temperature, stability, gain nonuniformity and phase-shift as function of frequency of interest for beam cooling systems are discussed

  17. Molecular beam epitaxy of gallium arsenide antimonide-based ultra-high-speed double heterojunction bipolar transistors and light emitting transistors

    Science.gov (United States)

    Wu, Bing-Ruey

    In this work, GaAsSb-based double heterojunction bipolar transistors (DHBTs) and light emitting transistors (LETs) are grown using gas source molecular beam epitaxy (GSMBE). High-speed GaAs0.5Sb0.5/InP DHBTs are developed through the exercise of GSMBE growth optimization, device fabrication, and characterization. By adjusting the growth temperature and V/III flux ratio, the optimal conditions for growing GaAs0.5Sb0.5 base are found to be at high growth temperature and low V/III ratio. The switching sequence is also optimized so that the Sb segregation effect is minimized. By using GaAs0.5Sb0.5-In0.2Ga0.8As 0.7Sb0.3 compositional grading in the base of the GaAsSb/InP DHBT, a significant improvement of fT from 380 GHz to 500 GHz was achieved compared to a uniform GaAs0.5Sb 0.5 DHBT, while maintaining a high breakdown voltage BVCEO ˜ 4V. The cutoff frequency---breakdown voltage product, fT·BVCEO, of over 2000 GHz-V, is the record value for DHBTs of any material system. Incorporating graded InAs-InGaAs emitter contact layer is also shown to effectively reduce the total emitter resistance, further improving the DHBT high speed performance. LET characteristics with quantum wells (QWs) inserted into the base region of GaAsSb/InP DHBTs are also investigated and the preliminary results are presented. An LET with a tensile strained InGaAsSb/GaAs0.65Sb 0.35 DQW in the base was designed and achieved the emission wavelength of ˜1.6 mum, despite of its low light output intensity. The potential and limitation of realizing a transistor laser with an emission wavelength of 1.55 mum using GaAsSb/InP material system will be discussed.

  18. Gallium Arsenide

    Science.gov (United States)

    Brozel, Mike

    The history of gallium arsenide is complicated because the technology required to produce GaAs devices has been fraught with problems associated with the material itself and with difficulties in its fabrication. Thus, for many years, GaAs was labelled as "the semiconductor of the future, and it will always be that way." Recently, however, advances in compact-disc (CD) technology, fibre-optic communications and mobile telephony have boosted investment in GaAs research and development. Consequently, there have been advances in materials and fabrication technology and, as a result, GaAs devices now enjoy stable niche markets.

  19. Transistors

    CERN Document Server

    Kendall, E J M

    2013-01-01

    Transistors covers the main thread of transistor development. This book is organized into 2 parts encompassing 19, and starts with an overview of the semi-conductor physics pertinent to the understanding of transistors, as well as features and applications of the point contact devices and junction devices. The subsequent part deals with the modulation of conductance of thin films of conductors by surface charges, the metal-semi conductor, and the semi-conductor triode. These topics are followed by discussions on the nature of the forward current, physical principles in transistor, the hole inj

  20. Spin Injection in Indium Arsenide

    Directory of Open Access Journals (Sweden)

    Mark eJohnson

    2015-08-01

    Full Text Available In a two dimensional electron system (2DES, coherent spin precession of a ballistic spin polarized current, controlled by the Rashba spin orbit interaction, is a remarkable phenomenon that’s been observed only recently. Datta and Das predicted this precession would manifest as an oscillation in the source-drain conductance of the channel in a spin-injected field effect transistor (Spin FET. The indium arsenide single quantum well materials system has proven to be ideal for experimental confirmation. The 2DES carriers have high mobility, low sheet resistance, and high spin orbit interaction. Techniques for electrical injection and detection of spin polarized carriers were developed over the last two decades. Adapting the proposed Spin FET to the Johnson-Silsbee nonlocal geometry was a key to the first experimental demonstration of gate voltage controlled coherent spin precession. More recently, a new technique measured the oscillation as a function of channel length. This article gives an overview of the experimental phenomenology of the spin injection technique. We then review details of the application of the technique to InAs single quantum well (SQW devices. The effective magnetic field associated with Rashba spin-orbit coupling is described, and a heuristic model of coherent spin precession is presented. The two successful empirical demonstrations of the Datta Das conductance oscillation are then described and discussed.

  1. Long-Term Characterization of 6H-SiC Transistor Integrated Circuit Technology Operating at 500 C

    Science.gov (United States)

    Neudeck, Philip G.; Spry, David J.; Chen, Liang-Yu; Chang, Carl W.; Beheim, Glenn M.; Okojie, Robert S.; Evans, Laura J.; Meredith Roger D.; Ferrier, Terry L.; Krasowski, Michael J.; Prokop, Norman F.

    2008-01-01

    NASA has been developing very high temperature semiconductor integrated circuits for use in the hot sections of aircraft engines and for Venus exploration. This paper reports on long-term 500 C electrical operation of prototype 6H-SiC integrated circuits based on epitaxial 6H-SiC junction field effect transistors (JFETs). As of this writing, some devices have surpassed 4000 hours of continuous 500 C electrical operation in oxidizing air atmosphere with minimal change in relevant electrical parameters.

  2. Pinch-off Voltage-adjustable High-voltage Junction Field-effect Transistor%夹断电压可调的高压结型场效应管

    Institute of Scientific and Technical Information of China (English)

    聂卫东; 朱光荣; 易法友; 于宗光

    2014-01-01

    基于Double RESURF 700 V BCD工艺平台,提出了一种夹断电压可调的高压结性场效应管(J-FET).这种J-FET的夹断是通过栅源反偏引起的N阱(N-well)表面耗尽和衬源反偏引起的底部耗尽共同作用结果,故夹断电压可受J-FET的栅电位调制.同时通过改变高压J-FET的P型埋层(P-buried)掩膜窗口的大小和间距,来改变P-buried和N-well的杂质浓度分布,达到改变J-FET夹断电压的目的.在不增加工艺步骤和改变原有工艺条件的情况下,通过实验得到击穿电压大于700 V,夹断电压在8V和17V之间可自由调整的高压J-FET器件.该器件可以作为启动器件和供电模块的线性调整器件使用.由于其夹断电压受P-buried注入版图尺寸的影响,同时受栅电位调制,所以可以满足线路设计者的不同要求.

  3. Window structure for passivating solar cells based on gallium arsenide

    Science.gov (United States)

    Barnett, Allen M. (Inventor)

    1985-01-01

    Passivated gallium arsenide solar photovoltaic cells with high resistance to moisture and oxygen are provided by means of a gallium arsenide phosphide window graded through its thickness from arsenic rich to phosphorus rich.

  4. Radiation effect on silicon transistors in mixed neutrons–gamma environment

    International Nuclear Information System (INIS)

    The effects of gamma and neutron irradiations on two different types of transistors, Junction Field Effect Transistor (JFET) and Bipolar Junction Transistor (BJT), were investigated. Irradiation was performed using a Syrian research reactor (RR) (Miniature Neutron Source Reactor (MNSR)) and a gamma source (Co-60 cell). For RR irradiation, MCNP code was used to calculate the absorbed dose received by the transistors. The experimental results showed an overall decrease in the gain factors of the transistors after irradiation, and the JFETs were more resistant to the effects of radiation than BJTs. The effect of RR irradiation was also greater than that of gamma source for the same dose, which could be because neutrons could cause more damage than gamma irradiation. - Highlights: • We measure the gain degradation after irradiation of BJT and JFET transistors. • We model the reactor and transistors in order to calculate irradiation dose. • The gain degradation was higher in BJT than in JFET. • Neutrons and gamma dose contributions of reactor were 2% and 98%, respectively. • The highest neutron contribution comes from the fast and resonance absorption neutrons

  5. Homo-junction ferroelectric field-effect-transistor memory device using solution-processed lithium-doped zinc oxide thin films

    KAUST Repository

    Nayak, Pradipta K.

    2012-06-22

    High performance homo-junction field-effect transistor memory devices were prepared using solution processed transparent lithium-doped zinc oxide thin films for both the ferroelectric and semiconducting active layers. A highest field-effect mobility of 8.7 cm2/Vs was obtained along with an Ion/Ioff ratio of 106. The ferroelectric thin filmtransistors showed a low sub-threshold swing value of 0.19 V/dec and a significantly reduced device operating voltage (±4 V) compared to the reported hetero-junction ferroelectrictransistors, which is very promising for low-power non-volatile memory applications.

  6. A terminal molybdenum arsenide complex synthesized from yellow arsenic.

    Science.gov (United States)

    Curley, John J; Piro, Nicholas A; Cummins, Christopher C

    2009-10-19

    A terminal molybdenum arsenide complex is synthesized in one step from the reactive As(4) molecule. The properties of this complex with its arsenic atom ligand are discussed in relation to the analogous nitride and phosphide complexes. PMID:19764796

  7. Gallium arsenide solar array subsystem study

    Science.gov (United States)

    Miller, F. Q.

    1982-01-01

    The effects on life cycle costs of a number of technology areas are examined for a gallium arsenide space solar array. Four specific configurations were addressed: (1) a 250 KWe LEO mission - planer array; (2) a 250 KWe LEO mission - with concentration; (3) a 50 KWe GEO mission planer array; (4) a 50 KWe GEO mission - with concentration. For each configuration, a baseline system conceptual design was developed and the life cycle costs estimated in detail. The baseline system requirements and design technologies were then varied and their relationships to life cycle costs quantified. For example, the thermal characteristics of the baseline design are determined by the array materials and masses. The thermal characteristics in turn determine configuration, performance, and hence life cycle costs.

  8. 6H-SiC Transistor Integrated Circuits Demonstrating Prolonged Operation at 500 C

    Science.gov (United States)

    Neudeck, Philip G.; Spry, David J.; Chen, Liang-Yu; Chang, Carl W.; Beheim, Glenn M.; Okojie, Robert S.; Evans, Laura J.; Meredith, Roger; Ferrier, Terry; Krasowski, Michael J.; Prokop, Norman F.

    2008-01-01

    The NASA Glenn Research Center is developing very high temperature semiconductor integrated circuits (ICs) for use in the hot sections of aircraft engines and for Venus exploration where ambient temperatures are well above the approximately 300 degrees Centigrade effective limit of silicon-on-insulator IC technology. In order for beneficial technology insertion to occur, such transistor ICs must be capable of prolonged operation in such harsh environments. This paper reports on the fabrication and long-term 500 degrees Centigrade operation of 6H-SiC integrated circuits based on epitaxial 6H-SiC junction field effect transistors (JFETs). Simple analog amplifier and digital logic gate ICs have now demonstrated thousands of hours of continuous 500 degrees Centigrade operation in oxidizing air atmosphere with minimal changes in relevant electrical parameters. Electrical characterization and modeling of transistors and circuits at temperatures from 24 degrees Centigrade to 500 degrees Centigrade is also described. Desired analog and digital IC functionality spanning this temperature range was demonstrated without changing the input signals or power supply voltages.

  9. Inhalation developmental toxicology studies: Gallium arsenide in mice and rats

    Energy Technology Data Exchange (ETDEWEB)

    Mast, T.J.; Greenspan, B.J.; Dill, J.A.; Stoney, K.H.; Evanoff, J.J.; Rommereim, R.L.

    1990-12-01

    Gallium arsenide is a crystalline compound used extensively in the semiconductor industry. Workers preparing solar cells and gallium arsenide ingots and wafers are potentially at risk from the inhalation of gallium arsenide dust. The potential for gallium arsenide to cause developmental toxicity was assessed in Sprague- Dawley rats and CD-1 (Swiss) mice exposed to 0, 10, 37, or 75 mg/m{sup 3} gallium arsenide, 6 h/day, 7 days/week. Each of the four treatment groups consisted of 10 virgin females (for comparison), and {approx}30 positively mated rats or {approx}24 positively mated mice. Mice were exposed on 4--17 days of gestation (dg), and rats on 4--19 dg. The day of plug or sperm detection was designated as 0 dg. Body weights were obtained throughout the study period, and uterine and fetal body weights were obtained at sacrifice (rats, 20 dg; mice, 18 dg). Implants were enumerated and their status recorded. Live fetuses were sexed and examined for gross, visceral, skeletal, and soft-tissue craniofacial defects. Gallium and arsenic concentrations were determined in the maternal blood and uterine contents of the rats (3/group) at 7, 14, and 20 dg. 37 refs., 11 figs., 30 tabs.

  10. Framework structures of interconnected layers in calcium iron arsenides.

    Science.gov (United States)

    Stürzer, Tobias; Hieke, Christine; Löhnert, Catrin; Nitsche, Fabian; Stahl, Juliane; Maak, Christian; Pobel, Roman; Johrendt, Dirk

    2014-06-16

    The new calcium iron arsenide compounds Ca(n(n+1)/2)(Fe(1-x)M(x))(2+3n)M'(n(n-1)/2)As((n+1)(n+2)/2) (n = 1-3; M = Nb, Pd, Pt; M' = □, Pd, Pt) were synthesized and their crystal structures determined by single-crystal X-ray diffraction. The series demonstrates the structural flexibility of iron arsenide materials, which otherwise prefer layered structures, as is known from the family of iron-based superconductors. In the new compounds, iron arsenide tetrahedral layers are bridged by iron-centered pyramids, giving rise to so far unknown frameworks of interconnected FeAs layers. Channels within the structures are occupied with calcium and palladium or platinum, respectively. Common basic building blocks are identified that lead to a better understanding of the building principles of these structures and their relation to CaFe4As3.

  11. Transport-reaction model for defect and carrier behavior within displacement cascades in gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Wampler, William R.; Myers, Samuel Maxwell,

    2014-02-01

    A model is presented for recombination of charge carriers at displacement damage in gallium arsenide, which includes clustering of the defects in atomic displacement cascades produced by neutron or ion irradiation. The carrier recombination model is based on an atomistic description of capture and emission of carriers by the defects with time evolution resulting from the migration and reaction of the defects. The physics and equations on which the model is based are presented, along with details of the numerical methods used for their solution. The model uses a continuum description of diffusion, field-drift and reaction of carriers and defects within a representative spherically symmetric cluster. The initial radial defect profiles within the cluster were chosen through pair-correlation-function analysis of the spatial distribution of defects obtained from the binary-collision code MARLOWE, using recoil energies for fission neutrons. Charging of the defects can produce high electric fields within the cluster which may influence transport and reaction of carriers and defects, and which may enhance carrier recombination through band-to-trap tunneling. Properties of the defects are discussed and values for their parameters are given, many of which were obtained from density functional theory. The model provides a basis for predicting the transient response of III-V heterojunction bipolar transistors to pulsed neutron irradiation.

  12. On the understanding of irradiation effects in germanium, silicon and gallium arsenide semi-conductors

    International Nuclear Information System (INIS)

    We have studied the behaviour of germanium, silicon and gallium arsenide semiconductors irradiated by different projectiles (heavy ions, protons, electrons and fullerenes). At low doses, thanks to deep level transient spectroscopy (DLTS) and Hall effect electrical measurements, we were able to explicit the nature of the defects present in germanium after irradiation at room temperature. For different projectiles, we have determined the defect creation kinetics. At higher doses, the electrical measurements have brought to the fore the presence of a specific defect created only after an heavy ion (or proton) irradiation. Moreover, positron annihilation spectroscopy (PAS) measurements show that size of this specific defect increases with the fluence. The damage has also been quantified by channeling Rutherford backscaterring (RBS-C) measurements. At first sight, the obtained defect creation rates are normalized by the nuclear collisions. This normalization is also present in the inverse of the gain evolution in silicon bipolar transistors. Meanwhile, an extensive study shows an efficiency decrease of the defect creation at intermediate values of the electronic energy loss Se, then, at the opposite, an increasing at higher values of Se. In the three semiconductors, we have observed track formation after fullerenes irradiation. These tracks are amorphous cylinders which have been characterized by transmission and high resolution electronic microscopy. They are due to the very high values of the electronic energy density which can be deposited by fullerenes owing to their low velocity. (author)

  13. Comparison of 6 Diode and 6 Transistor Mixers Based on Analysis and Measurement

    Directory of Open Access Journals (Sweden)

    J. Ladvánszky

    2016-01-01

    Full Text Available Our goal is to overview semiconductor mixers designed for good large signal performance. Twelve different mixers were compared utilizing pn diodes, bipolar transistors, and/or junction field effect transistors. The main aspect of comparison is the third-order intercept point (IP3, and both circuit analysis and measurement results have been considered. IP3 has been analyzed by the program AWR (NI AWR Design Environment and measured by two-tone test (Keysight Technologies. We provide three ways of improvement of large signal performance: application of a diplexer at the RF port, reduction of DC currents, and exploiting a region of RF input power with infinite IP3. In addition to that, our contributions are several modifications of existing mixers and a new mixer circuit (as illustrated in the figures. It is widely believed that the slope of the third-order intermodulation product versus input power is always greater than that of the first-order product. However, measurement and analysis revealed (as illustrated in the figures that the two lines may be parallel over a broad range of input power, thus resulting in infinite IP3. Mixer knowledge may be useful for a wide range of readers because almost every radio contains at least one mixer.

  14. Field-effect transistors based on cubic indium nitride.

    Science.gov (United States)

    Oseki, Masaaki; Okubo, Kana; Kobayashi, Atsushi; Ohta, Jitsuo; Fujioka, Hiroshi

    2014-02-04

    Although the demand for high-speed telecommunications has increased in recent years, the performance of transistors fabricated with traditional semiconductors such as silicon, gallium arsenide, and gallium nitride have reached their physical performance limits. Therefore, new materials with high carrier velocities should be sought for the fabrication of next-generation, ultra-high-speed transistors. Indium nitride (InN) has attracted much attention for this purpose because of its high electron drift velocity under a high electric field. Thick InN films have been applied to the fabrication of field-effect transistors (FETs), but the performance of the thick InN transistors was discouraging, with no clear linear-saturation output characteristics and poor on/off current ratios. Here, we report the epitaxial deposition of ultrathin cubic InN on insulating oxide yttria-stabilized zirconia substrates and the first demonstration of ultrathin-InN-based FETs. The devices exhibit high on/off ratios and low off-current densities because of the high quality top and bottom interfaces between the ultrathin cubic InN and oxide insulators. This first demonstration of FETs using a ultrathin cubic indium nitride semiconductor will thus pave the way for the development of next-generation high-speed electronics.

  15. Size-effects in indium gallium arsenide nanowire field-effect transistors

    Science.gov (United States)

    Zota, Cezar B.; Lind, E.

    2016-08-01

    We fabricate and analyze InGaAs nanowire MOSFETs with channel widths down to 18 nm. Low-temperature measurements reveal quantized conductance due to subband splitting, a characteristic of 1D systems. We relate these features to device performance at room-temperature. In particular, the threshold voltage versus nanowire width is explained by direct observation of quantization of the first sub-band, i.e., band gap widening. An analytical effective mass quantum well model is able to describe the observed band structure. The results reveal a compromise between reliability, i.e., VT variability, and on-current, through the mean free path, in the choice of the channel material.

  16. SiC JFET Transistor Circuit Model for Extreme Temperature Range

    Science.gov (United States)

    Neudeck, Philip G.

    2008-01-01

    A technique for simulating extreme-temperature operation of integrated circuits that incorporate silicon carbide (SiC) junction field-effect transistors (JFETs) has been developed. The technique involves modification of NGSPICE, which is an open-source version of the popular Simulation Program with Integrated Circuit Emphasis (SPICE) general-purpose analog-integrated-circuit-simulating software. NGSPICE in its unmodified form is used for simulating and designing circuits made from silicon-based transistors that operate at or near room temperature. Two rapid modifications of NGSPICE source code enable SiC JFETs to be simulated to 500 C using the well-known Level 1 model for silicon metal oxide semiconductor field-effect transistors (MOSFETs). First, the default value of the MOSFET surface potential must be changed. In the unmodified source code, this parameter has a value of 0.6, which corresponds to slightly more than half the bandgap of silicon. In NGSPICE modified to simulate SiC JFETs, this parameter is changed to a value of 1.6, corresponding to slightly more than half the bandgap of SiC. The second modification consists of changing the temperature dependence of MOSFET transconductance and saturation parameters. The unmodified NGSPICE source code implements a T(sup -1.5) temperature dependence for these parameters. In order to mimic the temperature behavior of experimental SiC JFETs, a T(sup -1.3) temperature dependence must be implemented in the NGSPICE source code. Following these two simple modifications, the Level 1 MOSFET model of the NGSPICE circuit simulation program reasonably approximates the measured high-temperature behavior of experimental SiC JFETs properly operated with zero or reverse bias applied to the gate terminal. Modification of additional silicon parameters in the NGSPICE source code was not necessary to model experimental SiC JFET current-voltage performance across the entire temperature range from 25 to 500 C.

  17. From Classical to Quantum Transistor

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar

    2009-05-01

    Full Text Available In this article the classical transistor and the basic physics underlying the operation of single electron transistor are presented; a brief history of transistor and current technological issues are discussed.

  18. One watt gallium arsenide class-E power amplifier with a thin-film bulk acoustic resonator filter embedded in the output network

    Directory of Open Access Journals (Sweden)

    Kyle Holzer

    2015-05-01

    Full Text Available Integration of a class-E power amplifier (PA and a thin-film bulk acoustic wave resonator (FBAR filter is shown to provide high power added efficiency in addition to superior out-of-band spectrum suppression. A discrete gallium arsenide pseudomorphic high-electron-mobility transistor is implemented to operate as a class-E amplifier from 2496 to 2690 MHz. The ACPF7041 compact bandpass FBAR filter is incorporated to replace the resonant LC tank in a traditional class-E PA. To reduce drain voltage stress, the supply choke is replaced by a finite inductance. The fabricated PA provides up to 1 W of output power with a peak power added efficiency (PAE of 58%. The improved out-of-band spectrum filtering is compared to a traditional class-E with discrete LC resonant filtering. Such PAs can be combined with linearisation techniques to reduce out-of-band emissions.

  19. Laser and electron beam processing of silicon and gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, J.

    1979-10-01

    Laser (photon) and electron beams provide a controlled source of heat by which surface layers of silicon and gallium arsenide can be rapidly melted and cooled with rates exceeding 10/sup 80/C/sec. The melting process has been used to remove displacement damage in ion implanted Si and GaAs, to remove dislocations, loops and precipitates in silicon and to study impurity segregation and solubility limits. The mechanisms associated with various phenomena will be examined. The possible impact of laser and electron beam processing on device technology, particularly with respect to solar cells is discussed.

  20. Macroscopic diffusion models for precipitation in crystalline gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Kimmerle, Sven-Joachim Wolfgang

    2009-09-21

    Based on a thermodynamically consistent model for precipitation in gallium arsenide crystals including surface tension and bulk stresses by Dreyer and Duderstadt, we propose two different mathematical models to describe the size evolution of liquid droplets in a crystalline solid. The first model treats the diffusion-controlled regime of interface motion, while the second model is concerned with the interface-controlled regime of interface motion. Our models take care of conservation of mass and substance. These models generalise the well-known Mullins- Sekerka model for Ostwald ripening. We concentrate on arsenic-rich liquid spherical droplets in a gallium arsenide crystal. Droplets can shrink or grow with time but the centres of droplets remain fixed. The liquid is assumed to be homogeneous in space. Due to different scales for typical distances between droplets and typical radii of liquid droplets we can derive formally so-called mean field models. For a model in the diffusion-controlled regime we prove this limit by homogenisation techniques under plausible assumptions. These mean field models generalise the Lifshitz-Slyozov-Wagner model, which can be derived from the Mullins-Sekerka model rigorously, and is well understood. Mean field models capture the main properties of our system and are well adapted for numerics and further analysis. We determine possible equilibria and discuss their stability. Numerical evidence suggests in which case which one of the two regimes might be appropriate to the experimental situation. (orig.)

  1. SiC Optically Modulated Field-Effect Transistor

    Science.gov (United States)

    Tabib-Azar, Massood

    2009-01-01

    An optically modulated field-effect transistor (OFET) based on a silicon carbide junction field-effect transistor (JFET) is under study as, potentially, a prototype of devices that could be useful for detecting ultraviolet light. The SiC OFET is an experimental device that is one of several devices, including commercial and experimental photodiodes, that were initially evaluated as detectors of ultraviolet light from combustion and that could be incorporated into SiC integrated circuits to be designed to function as combustion sensors. The ultraviolet-detection sensitivity of the photodiodes was found to be less than desired, such that it would be necessary to process their outputs using high-gain amplification circuitry. On the other hand, in principle, the function of the OFET could be characterized as a combination of detection and amplification. In effect, its sensitivity could be considerably greater than that of a photodiode, such that the need for amplification external to the photodetector could be reduced or eliminated. The experimental SiC OFET was made by processes similar to JFET-fabrication processes developed at Glenn Research Center. The gate of the OFET is very long, wide, and thin, relative to the gates of typical prior SiC JFETs. Unlike in prior SiC FETs, the gate is almost completely transparent to near-ultraviolet and visible light. More specifically: The OFET includes a p+ gate layer less than 1/4 m thick, through which photons can be transported efficiently to the p+/p body interface. The gate is relatively long and wide (about 0.5 by 0.5 mm), such that holes generated at the body interface form a depletion layer that modulates the conductivity of the channel between the drain and the source. The exact physical mechanism of modulation of conductivity is a subject of continuing research. It is known that injection of minority charge carriers (in this case, holes) at the interface exerts a strong effect on the channel, resulting in amplification

  2. Temperature dependence of carrier capture by defects in gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Wampler, William R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Modine, Normand A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-08-01

    This report examines the temperature dependence of the capture rate of carriers by defects in gallium arsenide and compares two previously published theoretical treatments of this based on multi phonon emission (MPE). The objective is to reduce uncertainty in atomistic simulations of gain degradation in III-V HBTs from neutron irradiation. A major source of uncertainty in those simulations is poor knowledge of carrier capture rates, whose values can differ by several orders of magnitude between various defect types. Most of this variation is due to different dependence on temperature, which is closely related to the relaxation of the defect structure that occurs as a result of the change in charge state of the defect. The uncertainty in capture rate can therefore be greatly reduced by better knowledge of the defect relaxation.

  3. Methods for forming group III-arsenide-nitride semiconductor materials

    Science.gov (United States)

    Major, Jo S. (Inventor); Welch, David F. (Inventor); Scifres, Donald R. (Inventor)

    2002-01-01

    Methods are disclosed for forming Group III-arsenide-nitride semiconductor materials. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V crystals varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V crystals can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired.

  4. First principles predictions of intrinsic defects in aluminum arsenide, AlAs : numerical supplement.

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Peter Andrew

    2012-04-01

    This Report presents numerical tables summarizing properties of intrinsic defects in aluminum arsenide, AlAs, as computed by density functional theory. This Report serves as a numerical supplement to the results published in: P.A. Schultz, 'First principles predictions of intrinsic defects in Aluminum Arsenide, AlAs', Materials Research Society Symposia Proceedings 1370 (2011; SAND2011-2436C), and intended for use as reference tables for a defect physics package in device models.

  5. Silicon nanowire transistors

    CERN Document Server

    Bindal, Ahmet

    2016-01-01

    This book describes the n and p-channel Silicon Nanowire Transistor (SNT) designs with single and dual-work functions, emphasizing low static and dynamic power consumption. The authors describe a process flow for fabrication and generate SPICE models for building various digital and analog circuits. These include an SRAM, a baseband spread spectrum transmitter, a neuron cell and a Field Programmable Gate Array (FPGA) platform in the digital domain, as well as high bandwidth single-stage and operational amplifiers, RF communication circuits in the analog domain, in order to show this technology’s true potential for the next generation VLSI. Describes Silicon Nanowire (SNW) Transistors, as vertically constructed MOS n and p-channel transistors, with low static and dynamic power consumption and small layout footprint; Targets System-on-Chip (SoC) design, supporting very high transistor count (ULSI), minimal power consumption requiring inexpensive substrates for packaging; Enables fabrication of different types...

  6. High Power Switching Transistor

    Science.gov (United States)

    Hower, P. L.; Kao, Y. C.; Carnahan, D. C.

    1983-01-01

    Improved switching transistors handle 400-A peak currents and up to 1,200 V. Using large diameter silicon wafers with twice effective area as D60T, form basis for D7 family of power switching transistors. Package includes npn wafer, emitter preform, and base-contact insert. Applications are: 25to 50-kilowatt high-frequency dc/dc inverters, VSCF converters, and motor controllers for electrical vehicles.

  7. Diode, transistor & fet circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Diode, Transistor and FET Circuits Manual is a handbook of circuits based on discrete semiconductor components such as diodes, transistors, and FETS. The book also includes diagrams and practical circuits. The book describes basic and special diode characteristics, heat wave-rectifier circuits, transformers, filter capacitors, and rectifier ratings. The text also presents practical applications of associated devices, for example, zeners, varicaps, photodiodes, or LEDs, as well as it describes bipolar transistor characteristics. The transistor can be used in three basic amplifier configuration

  8. Quantum thermal transistor

    CERN Document Server

    Joulain, Karl; Ezzahri, Younès; Ordonez-Miranda, Jose

    2016-01-01

    We demonstrate that a thermal transistor can be made up with a quantum system of 3 interacting subsystems , coupled to a thermal reservoir each. This thermal transistor is analogous to an electronic bipolar one with the ability to control the thermal currents at the collector and at the emitter with the imposed thermal current at the base. This is achieved determining the heat fluxes by means of the strong-coupling formalism. For the case of 3 interacting spins, in which one of them is coupled to the other 2, that are not directly coupled, it is shown that high amplification can be obtained in a wide range of energy parameters and temperatures. The proposed quantum transistor could, in principle, be used to develop devices such as a thermal modulator and a thermal amplifier in nano systems.

  9. Gallium Arsenide (GaAs) Quantum Photonic Waveguide Circuits

    CERN Document Server

    Wang, Jianwei; Jiang, Pisu; Bonneau, Damien; Engin, Erman; Silverstone, Joshua W; Lermer, Matthias; Beetz, Johannes; Kamp, Martin; Hofling, Sven; Tanner, Michael G; Natarajan, Chandra M; Hadfield, Robert H; Dorenbos, Sander N; Zwiller, Val; O'Brien, Jeremy L; Thompson, Mark G

    2014-01-01

    Integrated quantum photonics is a promising approach for future practical and large-scale quantum information processing technologies, with the prospect of on-chip generation, manipulation and measurement of complex quantum states of light. The gallium arsenide (GaAs) material system is a promising technology platform, and has already successfully demonstrated key components including waveguide integrated single-photon sources and integrated single-photon detectors. However, quantum circuits capable of manipulating quantum states of light have so far not been investigated in this material system. Here, we report GaAs photonic circuits for the manipulation of single-photon and two-photon states. Two-photon quantum interference with a visibility of 94.9 +/- 1.3% was observed in GaAs directional couplers. Classical and quantum interference fringes with visibilities of 98.6 +/- 1.3% and 84.4 +/- 1.5% respectively were demonstrated in Mach-Zehnder interferometers exploiting the electro-optic Pockels effect. This w...

  10. Noble Metal Arsenides and Gold Inclusions in Northwest Africa 8186

    Science.gov (United States)

    Srinivasan, P.; Agee, C. B.; McCubbin, F. M.; Rahman, Z.; Keller, L. P.

    2016-01-01

    CK carbonaceous chondrites are a highly thermally altered group of carbonaceous chondrites, experiencing temperatures ranging between approx.576-867 C. Additionally, the mineralogy of the CK chondrites record the highest overall oxygen fugacity of all chondrites, above the fayalite-magnetite-quartz (FMQ) buffer. Metallic Fe-Ni is extremely rare in CK chondrites, but magnetite and Fe,Ni sulfides are commonly observed. Noble metal-rich inclusions have previously been found in some magnetite and sulfide grains. These arsenides, tellurides, and sulfides, which contain varying amounts of Pt, Ru, Os, Te, As, Ir, and S, are thought to form either by condensation from a solar gas, or by exsolution during metamorphism on the chondritic parent body. Northwest Africa (NWA) 8186 is a highly metamorphosed CK chondrite. This meteorite is predominately composed of NiO-rich forsteritic olivine (Fo65), with lesser amounts of plagioclase (An52), augite (Fs11Wo49), magnetite (with exsolved titanomagnetite, hercynite, and titanohematite), monosulfide solid solution (with exsolved pentlandite), and the phosphate minerals Cl-apatite and merrillite. This meteorite contains coarse-grained, homogeneous silicates, and has 120deg triple junctions between mineral phases, which indicates a high degree of thermal metamorphism. The presence of NiO-rich olivine, oxides phases all bearing Fe3+, and the absence of metal, are consistent with an oxygen fugacity above the FMQ buffer. We also observed noble metal-rich phases within sulfide grains in NWA 8186, which are the primary focus of the present study.

  11. Mesoscopic photon heat transistor

    DEFF Research Database (Denmark)

    Ojanen, T.; Jauho, Antti-Pekka

    2008-01-01

    We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit-leading to the device concept of a mesoscopic photon heat transistor (MPHT). Our theoretical analysis is based on a novel Meir-Wingreen-Landauer-typ......We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit-leading to the device concept of a mesoscopic photon heat transistor (MPHT). Our theoretical analysis is based on a novel Meir...

  12. Accelerating the life of transistors

    Institute of Scientific and Technical Information of China (English)

    Qi Haochun; Lü Changzhi; Zhang Xiaoling; Xie Xuesong

    2013-01-01

    Choosing small and medium power switching transistors of the NPN type in a 3DK set as the study object,the test of accelerating life is conducted in constant temperature and humidity,and then the data are statistically analyzed with software developed by ourselves.According to degradations of such sensitive parameters as the reverse leakage current of transistors,the lifetime order of transistors is about more than 104 at 100 ℃ and 100% relative humidity (RH) conditions.By corrosion fracture of transistor outer leads and other failure modes,with the failure truncated testing,the average lifetime rank of transistors in different distributions is extrapolated about 103.Failure mechanism analyses of degradation of electrical parameters,outer lead fracture and other reasons that affect transistor lifetime are conducted.The findings show that the impact of external stress of outer leads on transistor reliability is more serious than that of parameter degradation.

  13. Accelerating the life of transistors

    Science.gov (United States)

    Haochun, Qi; Changzhi, Lü; Xiaoling, Zhang; Xuesong, Xie

    2013-06-01

    Choosing small and medium power switching transistors of the NPN type in a 3DK set as the study object, the test of accelerating life is conducted in constant temperature and humidity, and then the data are statistically analyzed with software developed by ourselves. According to degradations of such sensitive parameters as the reverse leakage current of transistors, the lifetime order of transistors is about more than 104 at 100 °C and 100% relative humidity (RH) conditions. By corrosion fracture of transistor outer leads and other failure modes, with the failure truncated testing, the average lifetime rank of transistors in different distributions is extrapolated about 103. Failure mechanism analyses of degradation of electrical parameters, outer lead fracture and other reasons that affect transistor lifetime are conducted. The findings show that the impact of external stress of outer leads on transistor reliability is more serious than that of parameter degradation.

  14. The comparison between gallium arsenide and indium gallium arsenide as materials for solar cell performance using Silvaco application

    Energy Technology Data Exchange (ETDEWEB)

    Zahari, Suhaila Mohd; Norizan, Mohd Natashah; Mohamad, Ili Salwani; Osman, Rozana Aina Maulat; Taking, Sanna [School of Microelectronic Engineering, Universiti Malaysia Perlis, Kampus Pauh Putra, 02600 Arau, Perlis (Malaysia)

    2015-05-15

    The work presented in this paper is about the development of single and multilayer solar cells using GaAs and InGaAs in AM1.5 condition. The study includes the modeling structure and simulation of the device using Silvaco applications. The performance in term of efficiency of Indium Gallium Arsenide (InGaAs) and GaAs material was studied by modification of the doping concentration and thickness of material in solar cells. The efficiency of the GaAs solar cell was higher than InGaAs solar cell for single layer solar cell. Single layer GaAs achieved an efficiency about 25% compared to InGaAs which is only 2.65% of efficiency. For multilayer which includes both GaAs and InGaAs, the output power, P{sub max} was 8.91nW/cm² with the efficiency only 8.51%. GaAs is one of the best materials to be used in solar cell as a based compared to InGaAs.

  15. A study of the applicability of gallium arsenide and silicon carbide as aerospace sensor materials

    Science.gov (United States)

    Hurley, John S.

    1990-01-01

    Most of the piezoresistive sensors, to date, are made of silicon and germanium. Unfortunately, such materials are severly restricted in high temperature environments. By comparing the effects of temperature on the impurity concentrations and piezoresistive coefficients of silicon, gallium arsenide, and silicon carbide, it is being determined if gallium arsenide and silicon carbide are better suited materials for piezoresistive sensors in high temperature environments. The results show that the melting point for gallium arsenide prevents it from solely being used in high temperature situations, however, when used in the alloy Al(x)Ga(1-x)As, not only the advantage of the wider energy band gas is obtained, but also the higher desire melting temperature. Silicon carbide, with its wide energy band gap and higher melting temperature suggests promise as a high temperature piezoresistive sensor.

  16. Surface-enhanced gallium arsenide photonic resonator with a quality factor of six million

    CERN Document Server

    Guha, Biswarup; Cadiz, Fabian; Morgenroth, Laurence; Ulin, Vladimir; Berkovitz, Vladimir; Lemaître, Aristide; Gomez, Carmen; Amo, Alberto; Combrié, Sylvian; Gérard, Bruno; Leo, Giuseppe; Favero, Ivan

    2016-01-01

    Gallium Arsenide and related compound semiconductors lie at the heart of optoelectronics and integrated laser technologies. Shaped at the micro and nano-scale, they allow strong interaction with quantum dots and quantum wells, and promise to result in stunning devices. However gallium arsenide optical structures presently exhibit lower performances than their silicon-based counterparts, notably in nanophotonics where the surface plays a chief role. Here we report on advanced surface control of miniature gallium arsenide optical resonators, using two distinct techniques that produce permanent results. One leads to extend the lifetime of free-carriers and enhance luminescence, while the other strongly reduces surface absorption originating from mid-gap states and enables ultra-low optical dissipation devices. With such surface control, the quality factor of wavelength-sized optical disk resonators is observed to rise up to six million at telecom wavelength, greatly surpassing previous realizations and opening n...

  17. A Matterwave Transistor Oscillator

    CERN Document Server

    Caliga, Seth C; Zozulya, Alex A; Anderson, Dana Z

    2012-01-01

    A triple-well atomtronic transistor combined with forced RF evaporation is used to realize a driven matterwave oscillator circuit. The transistor is implemented using a metalized compound glass and silicon substrate. On-chip and external currents produce a cigar-shaped magnetic trap, which is divided into transistor source, gate, and drain regions by a pair of blue-detuned optical barriers projected onto the magnetic trap through a chip window. A resonant laser beam illuminating the drain portion of the atomtronic transistor couples atoms emitted by the gate to the vacuum. The circuit operates by loading the source with cold atoms and utilizing forced evaporation as a power supply that produces a positive chemical potential in the source, which subsequently drives oscillation. High-resolution in-trap absorption imagery reveals gate atoms that have tunneled from the source and establishes that the circuit emits a nominally mono-energetic matterwave with a frequency of 23.5(1.0) kHz by tunneling from the gate, ...

  18. Spin-torque transistor

    NARCIS (Netherlands)

    Bauer, G.E.W.; Brataas, A.; Tserkovnyak, Y.; Van Wees, B.J.

    2003-01-01

    A magnetoelectronic thin-film transistor is proposed that can display negative differential resistance and gain. The working principle is the modulation of the soure–drain current in a spin valve by the magnetization of a third electrode, which is rotated by the spin-torque created by a control spin

  19. Vertical organic transistors

    International Nuclear Information System (INIS)

    Organic switching devices such as field effect transistors (OFETs) are a key element of future flexible electronic devices. So far, however, a commercial breakthrough has not been achieved because these devices usually lack in switching speed (e.g. for logic applications) and current density (e.g. for display pixel driving). The limited performance is caused by a combination of comparatively low charge carrier mobilities and the large channel length caused by the need for low-cost structuring. Vertical Organic Transistors are a novel technology that has the potential to overcome these limitations of OFETs. Vertical Organic Transistors allow to scale the channel length of organic transistors into the 100 nm regime without cost intensive structuring techniques. Several different approaches have been proposed in literature, which show high output currents, low operation voltages, and comparatively high speed even without sub-μm structuring technologies. In this review, these different approaches are compared and recent progress is highlighted. (topical review)

  20. Radiation-hardened transistor and integrated circuit

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Kwok K. (Albuquerque, NM)

    2007-11-20

    A composite transistor is disclosed for use in radiation hardening a CMOS IC formed on an SOI or bulk semiconductor substrate. The composite transistor has a circuit transistor and a blocking transistor connected in series with a common gate connection. A body terminal of the blocking transistor is connected only to a source terminal thereof, and to no other connection point. The blocking transistor acts to prevent a single-event transient (SET) occurring in the circuit transistor from being coupled outside the composite transistor. Similarly, when a SET occurs in the blocking transistor, the circuit transistor prevents the SET from being coupled outside the composite transistor. N-type and P-type composite transistors can be used for each and every transistor in the CMOS IC to radiation harden the IC, and can be used to form inverters and transmission gates which are the building blocks of CMOS ICs.

  1. Progress to a Gallium-Arsenide Deep-Center Laser

    Directory of Open Access Journals (Sweden)

    Janet L. Pan

    2009-10-01

    Full Text Available Although photoluminescence from gallium-arsenide (GaAs deep-centers was first observed in the 1960s, semiconductor lasers have always utilized conduction-to-valence-band transitions. Here we review recent materials studies leading to the first GaAs deep-center laser. First, we summarize well-known properties: nature of deep-center complexes, Franck-Condon effect, hotoluminescence. Second, we describe our recent work: insensitivity of photoluminescence with heating, striking differences between electroluminescence and photoluminescence, correlation between transitions to deep-states and absence of bandgap-emission. Room-temperature stimulated-emission from GaAs deep-centers was observed at low electrical injection, and could be tuned from the bandgap to half-the-bandgap (900–1,600 nm by changing the electrical injection. The first GaAs deep-center laser was demonstrated with electrical injection, and exhibited a threshold of less than 27 mA/cm2 in continuous-wave mode at room temperature at the important 1.54 μm fiber-optic wavelength. This small injection for laser action was explained by fast depopulation of the lower state of the optical transition (fast capture of free holes onto deep-centers, which maintains the population inversion. The evidence for laser action included: superlinear L-I curve, quasi-Fermi level separations satisfying Bernard-Duraffourg’s criterion, optical gains larger than known significant losses, clamping of the optical-emission from lossy modes unable to reach laser action, pinning of the population distribution during laser action.

  2. High-field phase-diagram of Fe arsenide superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Y.J.; Jaroszynski, J.; Yamamoto, A.; Gurevich, A.; Riggs, S.C.; Boebinger, G.S.; Larbalestier, D. [National High Magnetic Field Laboratory, Florida State University, Tallahassee-FL 32310 (United States); Wen, H.H. [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zhigadlo, N.D.; Katrych, S.; Bukowski, Z.; Karpinski, J. [Laboratory for Solid State Physics, ETH Zuerich, CH-8093 Zuerich (Switzerland); Liu, R.H.; Chen, H.; Chen, X.H. [Hefei National Laboratory for Physical Science a Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Balicas, L., E-mail: balicas@magnet.fsu.ed [National High Magnetic Field Laboratory, Florida State University, Tallahassee-FL 32310 (United States)

    2009-05-01

    Here, we report an overview of the phase-diagram of single-layered and double-layered Fe arsenide superconductors at high magnetic fields. Our systematic magneto-transport measurements of polycrystalline SmFeAsO{sub 1-x}F{sub x} at different doping levels confirm the upward curvature of the upper critical magnetic field H{sub c2}(T) as a function of temperature T defining the phase boundary between the superconducting and metallic states for crystallites with the ab planes oriented nearly perpendicular to the magnetic field. We further show from measurements on single-crystals that this feature, which was interpreted in terms of the existence of two superconducting gaps, is ubiquitous among both series of single- and double-layered compounds. In all compounds explored by us the zero temperature upper critical field H{sub c2}(0), estimated either through the Ginzburg-Landau or the Werthamer-Helfand-Hohenberg single gap theories, strongly surpasses the weak-coupling Pauli paramagnetic limiting field. This clearly indicates the strong-coupling nature of the superconducting state and the importance of magnetic correlations for these materials. Our measurements indicate that the superconducting anisotropy, as estimated through the ratio of the effective masses gamma = (m{sub c}/m{sub ab}){sup 1/2} for carriers moving along the c-axis and the ab-planes, respectively, is relatively modest as compared to the high-T{sub c} cuprates, but it is temperature, field and even doping dependent. Finally, our preliminary estimations of the irreversibility field H{sub m}(T), separating the vortex-solid from the vortex-liquid phase in the single-layered compounds, indicates that it is well described by the melting of a vortex lattice in a moderately anisotropic uniaxial superconductor.

  3. Noble Metal Arsenides and Gold Inclusions in Northwest Africa 8186

    Science.gov (United States)

    Srinivasan, P.; McCubbin, F. M.; Rahman, Z.; Keller, L. P.; Agee, C. B.

    2016-01-01

    CK carbonaceous chondrites are a highly thermally altered group of carbonaceous chondrites, experiencing temperatures ranging between approximately 576-867 degrees Centigrade. Additionally, the mineralogy of the CK chondrites record the highest overall oxygen fugacity of all chondrites, above the fayalite-magnetite-quartz (FMQ) buffer. Me-tallic Fe-Ni is extremely rare in CK chondrites, but magnetite and Fe,Ni sulfides are commonly observed. Noble metal-rich inclusions have previously been found in some magnetite and sulfide grains. These arsenides, tellurides, and sulfides, which contain varying amounts of Pt, Ru, Os, Te, As, Ir, and S, are thought to form either by condensation from a solar gas, or by exsolution during metamorphism on the chondritic parent body. Northwest Africa (NWA) 8186 is a highly metamorphosed CK chondrite. This meteorite is predominately composed of NiO-rich forsteritic olivine (Fo65), with lesser amounts of plagioclase (An52), augite (Fs11Wo49), magnetite (with exsolved titanomagnetite, hercynite, and titanohematite), monosulfide solid solution (with exsolved pentlandite), and the phosphate minerals Cl-apatite and merrillite. This meteorite contains coarse-grained, homogeneous silicates, and has 120-degree triple junctions between mineral phases, which indicates a high degree of thermal metamorphism. The presence of NiO-rich olivine, oxides phases all bearing Fe3 plus, and the absence of metal, are consistent with an oxygen fugacity above the FMQ buffer. We also observed noble metal-rich phases within sulfide grains in NWA 8186, which are the primary focus of the present study.

  4. Indium Phosphide Window Layers for Indium Gallium Arsenide Solar Cells

    Science.gov (United States)

    Jain, Raj K.

    2005-01-01

    Window layers help in reducing the surface recombination at the emitter surface of the solar cells resulting in significant improvement in energy conversion efficiency. Indium gallium arsenide (In(x)Ga(1-x)As) and related materials based solar cells are quite promising for photovoltaic and thermophotovoltaic applications. The flexibility of the change in the bandgap energy and the growth of InGaAs on different substrates make this material very attractive for multi-bandgap energy, multi-junction solar cell approaches. The high efficiency and better radiation performance of the solar cell structures based on InGaAs make them suitable for space power applications. This work investigates the suitability of indium phosphide (InP) window layers for lattice-matched In(0.53)Ga(0.47)As (bandgap energy 0.74 eV) solar cells. We present the first data on the effects of the p-type InP window layer on p-on-n lattice-matched InGaAs solar cells. The modeled quantum efficiency results show a significant improvement in the blue region with the InP window. The bare InGaAs solar cell performance suffers due to high surface recombination velocity (10(exp 7) cm/s). The large band discontinuity at the InP/InGaAs heterojunction offers a great potential barrier to minority carriers. The calculated results demonstrate that the InP window layer effectively passivates the solar cell front surface, hence resulting in reduced surface recombination and therefore, significantly improving the performance of the InGaAs solar cell.

  5. Silicon-on-insulator-based high-voltage, high-temperature integrated circuit gate driver for silicon carbide-based power field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Tolbert, Leon M [ORNL; Huque, Mohammad A [ORNL; Blalock, Benjamin J [ORNL; Islam, Syed K [ORNL

    2010-01-01

    Silicon carbide (SiC)-based field effect transistors (FETs) are gaining popularity as switching elements in power electronic circuits designed for high-temperature environments like hybrid electric vehicle, aircraft, well logging, geothermal power generation etc. Like any other power switches, SiC-based power devices also need gate driver circuits to interface them with the logic units. The placement of the gate driver circuit next to the power switch is optimal for minimising system complexity. Successful operation of the gate driver circuit in a harsh environment, especially with minimal or no heat sink and without liquid cooling, can increase the power-to-volume ratio as well as the power-to-weight ratio for power conversion modules such as a DC-DC converter, inverter etc. A silicon-on-insulator (SOI)-based high-voltage, high-temperature integrated circuit (IC) gate driver for SiC power FETs has been designed and fabricated using a commercially available 0.8--m, 2-poly and 3-metal bipolar-complementary metal oxide semiconductor (CMOS)-double diffused metal oxide semiconductor (DMOS) process. The prototype circuit-s maximum gate drive supply can be 40-V with peak 2.3-A sourcing/sinking current driving capability. Owing to the wide driving range, this gate driver IC can be used to drive a wide variety of SiC FET switches (both normally OFF metal oxide semiconductor field effect transistor (MOSFET) and normally ON junction field effect transistor (JFET)). The switching frequency is 20-kHz and the duty cycle can be varied from 0 to 100-. The circuit has been successfully tested with SiC power MOSFETs and JFETs without any heat sink and cooling mechanism. During these tests, SiC switches were kept at room temperature and ambient temperature of the driver circuit was increased to 200-C. The circuit underwent numerous temperature cycles with negligible performance degradation.

  6. Polarization induced doped transistor

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Huili (Grace); Jena, Debdeep; Nomoto, Kazuki; Song, Bo; Zhu, Mingda; Hu, Zongyang

    2016-06-07

    A nitride-based field effect transistor (FET) comprises a compositionally graded and polarization induced doped p-layer underlying at least one gate contact and a compositionally graded and doped n-channel underlying a source contact. The n-channel is converted from the p-layer to the n-channel by ion implantation, a buffer underlies the doped p-layer and the n-channel, and a drain underlies the buffer.

  7. Light transport through disordered layers of dense gallium arsenide submicron particles

    NARCIS (Netherlands)

    Van der Beek, T.; Barthelemy, P.J.C.; Johnson, P.M.; Wiersma, D.S.; Lagendijk, A.

    2012-01-01

    We present a study of optical transport properties of powder layers with submicrometer, strongly scattering gallium arsenide (GaAs) particles. Uniform, thin samples with well controlled thicknesses were created through the use of varying grinding times, sedimentation fractionation, annealing, and a

  8. Gallium interstitial contributions to diffusion in gallium arsenide

    Directory of Open Access Journals (Sweden)

    Joseph T. Schick

    2011-09-01

    have been encountered in fitting experimental results for heavily p-type, Ga-rich gallium arsenide by simply extending a model for gallium interstitial diffusion which has been used for less p-doped material.

  9. Spontaneous atomic ordering in MOVPE grown gallium arsenide antimonide

    Science.gov (United States)

    Jiang, Weiyang

    process. It is unlikely that the ordering mechanism is similar to the dimer-induced strain models that have been successfully used to explain CuPt ordering in InGaP. We propose a simple model based on alternating incorporation of group V adatoms at step edges. Keywords. GaAsSb; MOVPE; Bi surfactant; TEM; CuAu ordering. Subject. Gallium Arsenide Antimonide; Metalorganic Vapor-phase Epitaxy; Bismuth Surfactant; Transmission Electron Microscopy; CuAu Ordering.

  10. Boron, bismuth co-doping of gallium arsenide and other compounds for photonic and heterojunction bipolar transistor devices

    Science.gov (United States)

    Mascarenhas, Angelo

    2015-07-07

    Isoelectronic co-doping of semiconductor compounds and alloys with acceptors and deep donors is sued to decrease bandgap, to increase concentration of the dopant constituents in the resulting alloys, and to increase carrier mobilities lifetimes. For example, Group III-V compounds and alloys, such as GaAs and GaP, are isoelectronically co-doped with, for example, B and Bi, to customize solar cells, and other semiconductor devices. Isoelectronically co-doped Group II-VI compounds and alloys are also included.

  11. Biological availability of nickel arsenides: toxic effects of particulate Ni/sub 5/As/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Gurley, L.R.; Tobey, R.A.; Valdez, J.G.; Halleck, M.S.; Barham, S.S.

    1981-01-01

    Considerations of (1) oil shale retort operating conditions, (2) oil shale elemental composition, (3) nickel and arsenic physico-chemical properties, and (4) oil shale matrix structure lead to the suggestion that nickel arsenides may be formed during the oil shale retorting process. The biological effects of nickel arsenides have not been previously studied. However, similarities between nickel subarsenide and nickel subsulfide and nickel subselenimide, both of which are known potent carcinogens, have caused concern that nickel arsenides may have adverse effects on biological systems. To determine if fugitive nickel arsenides from an oil shale retort could pose a threat to personnel in the workplace or to other living organisms in the environment, a program to study the toxicity of nickel arsenides has been initiated. Five stable nickel arsenides (Ni/sub 5/As/sub 2/, Ni/sub 2/As, Ni/sub 11/As/sub 8/, NiAs, and NiAs/sub 2/) and nickel arsenic sulfide (NiAsS) are considered possible species for study.

  12. Monolithic metal oxide transistors.

    Science.gov (United States)

    Choi, Yongsuk; Park, Won-Yeong; Kang, Moon Sung; Yi, Gi-Ra; Lee, Jun-Young; Kim, Yong-Hoon; Cho, Jeong Ho

    2015-04-28

    We devised a simple transparent metal oxide thin film transistor architecture composed of only two component materials, an amorphous metal oxide and ion gel gate dielectric, which could be entirely assembled using room-temperature processes on a plastic substrate. The geometry cleverly takes advantage of the unique characteristics of the two components. An oxide layer is metallized upon exposure to plasma, leading to the formation of a monolithic source-channel-drain oxide layer, and the ion gel gate dielectric is used to gate the transistor channel effectively at low voltages through a coplanar gate. We confirmed that the method is generally applicable to a variety of sol-gel-processed amorphous metal oxides, including indium oxide, indium zinc oxide, and indium gallium zinc oxide. An inverter NOT logic device was assembled using the resulting devices as a proof of concept demonstration of the applicability of the devices to logic circuits. The favorable characteristics of these devices, including (i) the simplicity of the device structure with only two components, (ii) the benign fabrication processes at room temperature, (iii) the low-voltage operation under 2 V, and (iv) the excellent and stable electrical performances, together support the application of these devices to low-cost portable gadgets, i.e., cheap electronics. PMID:25777338

  13. The diamond RF-transistor model

    Directory of Open Access Journals (Sweden)

    Altukhov A. A.

    2011-12-01

    Full Text Available In this work is shown that fluent shutter model it is enough well describes work field-effect diamond RF-transistors. Using this model, possible to calculate transistor parameters used electronic parameters of the diamond structure with δ-doped (hydrogen or boron layer and geometric parameter transistor element. Proof, are calculated by us main parameters model RF-transistor, which it is enough close comply with published experimental result of the measurements real RF-transistors.

  14. First-Principles Determination of Ultrahigh Thermal Conductivity of Boron Arsenide: A Competitor for Diamond?

    Science.gov (United States)

    Lindsay, L.; Broido, D. A.; Reinecke, T. L.

    2013-07-01

    We have calculated the thermal conductivities (κ) of cubic III-V boron compounds using a predictive first principles approach. Boron arsenide is found to have a remarkable room temperature κ over 2000Wm-1K-1; this is comparable to those in diamond and graphite, which are the highest bulk values known. We trace this behavior in boron arsenide to an interplay of certain basic vibrational properties that lie outside of the conventional guidelines in searching for high κ materials, and to relatively weak phonon-isotope scattering. We also find that cubic boron nitride and boron antimonide will have high κ with isotopic purification. This work provides new insight into the nature of thermal transport at a quantitative level and predicts a new ultrahigh κ material of potential interest for passive cooling applications.

  15. Suppression of decoherence in gallium arsenide multiple quantum wells by means of bang-bang control

    Energy Technology Data Exchange (ETDEWEB)

    Takasago, K. [Department of Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan)], E-mail: takasago.k.aa@m.titech.ac.jp; Ogawa, Y.; Minami, F. [Department of Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan)

    2008-05-15

    We performed a three-pulse six-wave mixing (SWM) measurement on a gallium arsenide (GaAs) multiple quantum well and observed the time-resolved SWM signal using the heterodyne detection technique. The second pulse acts as a {pi} pulse that reverses the time evolution of the non-Markovian dynamics. By changing the pulse interval conditions, we confirmed the suppression of exciton decoherence by {pi} pulse irradiation (bang-bang control)

  16. Gate-enclosed NMOS transistors

    Institute of Scientific and Technical Information of China (English)

    Fan Xue; Li Ping; Li Wei; Zhang Bin; Xie Xiaodong; Wang Gang; Hu Bin; Zhai Yahong

    2011-01-01

    In order to quantitatively compare the design cost and performance of various gate styles,NMOS transistors with two-edged,annular and ring gate layouts were designed and fabricated by a commercial 0.35 μm CMOS process.By comparing the minimum W/L ratios and transistor areas,it was found that either the annular layout or its ring counterpart incurs a higher area penalty that depends on the W/L ratio of the transistor to be designed.Furthermore,by comparing the output and transfer characteristics of the transistors and analyzing the popular existing methods for extracting the effective W/L ratio,it was shown that the mid-line approximation for annular NMOS could incur an error of more than 10%.It was also demonstrated that the foundry-provided extraction tool needs significant adaptation when being applied to the enclosed-gate transistors,since it is targeted only toward the two-edged transistor.A simple approach for rough extraction of the W/L ratio for the ring-gate NMOS was presented and its effectiveness was confirmed by the experimental results with an error up to 8%.

  17. Electron tunneling transport across heterojunctions between europium sulfide and indium arsenide

    Science.gov (United States)

    Kallaher, Raymond L.

    This dissertation presents research done on utilizing the ferromagnetic semiconductor europium sulfide (EuS) to inject spin polarized electrons into the non-magnetic semiconductor indium arsenide (InAs). There is great interest in expanding the functionality of modern day electronic circuits by creating devices that depend not only on the flow of charge in the device, but also on the transport of spin through the device. Within this mindset, there is a concerted effort to establish an efficient means of injecting and detecting spin polarized electrons in a two dimensional electron system (2DES) as the first step in developing a spin based field effect transistor. Thus, the research presented in this thesis has focused on the feasibility of using EuS, in direct electrical contact with InAs, as a spin injecting electrode into an InAs 2DES. Doped EuS is a concentrated ferromagnetic semiconductor, whose conduction band undergoes a giant Zeeman splitting when the material becomes ferromagnetic. The concomitant difference in energy between the spin-up and spin-down energy bands makes the itinerant electrons in EuS highly spin polarized. Thus, in principle, EuS is a good candidate to be used as an injector of spin polarized electrons into non-magnetic materials. In addition, the ability to adjust the conductivity of EuS by varying the doping level in the material makes EuS particularly suited for injecting spins into non-magnetic semiconductors and 2DES. For this research, thin films of EuS have been grown via e-beam evaporation of EuS powder. This growth technique produces EuS films that are sulfur deficient; these sulfur vacancies act as intrinsic electron donors and the resulting EuS films behave like heavily doped ferromagnetic semiconductors. The growth parameters and deposition procedures were varied and optimized in order to fabricate films that have minimal crystalline defects. Various properties and characteristics of these EuS films were measured and compared to

  18. Quantum Point Contact Transistor and Ballistic Field-Effect Transistors

    International Nuclear Information System (INIS)

    We report the experimental results and theoretical understanding of the Quantum Point Contact Transistor - a fully ballistic one-dimensional (1D) Field-Effect Transistor (FET). Experimentally obtained voltage gain greater than 1 in our Quantum-Point-Contact transistors at 4.2 K can be explained with the help of an analytical modeling based on the Landauer-Büttiker approach in mesosopic physics: the lowest 1D subband and the band gap play the key role in increasing its transconductance, especially by reducing its output conductance, and thus achieving a voltage gain higher than 1. This work provides a general basis for devising future ballistic FETs and the quantum limits found in this work may be used to estimate normalized transconductance and channel resistance in future two-dimensional (2D) ballistic FETs.

  19. Passivated ambipolar black phosphorus transistors

    Science.gov (United States)

    Yue, Dewu; Lee, Daeyeong; Jang, Young Dae; Choi, Min Sup; Nam, Hye Jin; Jung, Duk-Young; Yoo, Won Jong

    2016-06-01

    We report the first air-passivated ambipolar BP transistor formed by applying benzyl viologen, which serves as a surface charge transfer donor for BP flakes. The passivated BP devices exhibit excellent stability under both an ambient atmosphere and vacuum; their transistor performance is maintained semi-permanently. Unlike their intrinsic p-type properties, passivated BP devices present advantageous ambipolar properties with much higher electron mobility up to ~83 cm2 V-1 s-1 from 2-terminal measurement at 300 K, compared to other reported studies on n-type BP transistors. On the basis of the n-type doping effect that originated from benzyl viologen, we also systematically investigated the BP thickness dependence of our devices on electrical properties, in which we found the best electron transport performance to be attained when an ~10 nm thick BP flake was used.We report the first air-passivated ambipolar BP transistor formed by applying benzyl viologen, which serves as a surface charge transfer donor for BP flakes. The passivated BP devices exhibit excellent stability under both an ambient atmosphere and vacuum; their transistor performance is maintained semi-permanently. Unlike their intrinsic p-type properties, passivated BP devices present advantageous ambipolar properties with much higher electron mobility up to ~83 cm2 V-1 s-1 from 2-terminal measurement at 300 K, compared to other reported studies on n-type BP transistors. On the basis of the n-type doping effect that originated from benzyl viologen, we also systematically investigated the BP thickness dependence of our devices on electrical properties, in which we found the best electron transport performance to be attained when an ~10 nm thick BP flake was used. Electronic supplementary information (ESI) available: Transfer characteristics of BP field effect transistors (BV1-BV4) (Fig. S1 and S2 and Table S1); output characteristics of BP field effect transistors in different directions (Fig. S3

  20. High current gain transistor laser

    Science.gov (United States)

    Liang, Song; Qiao, Lijun; Zhu, Hongliang; Wang, Wei

    2016-06-01

    A transistor laser (TL), having the structure of a transistor with multi-quantum wells near its base region, bridges the functionality gap between lasers and transistors. However, light emission is produced at the expense of current gain for all the TLs reported up to now, leading to a very low current gain. We propose a novel design of TLs, which have an n-doped InP layer inserted in the emitter ridge. Numerical studies show that a current flow aperture for only holes can be formed in the center of the emitter ridge. As a result, the common emitter current gain can be as large as 143.3, which is over 15 times larger than that of a TL without the aperture. Besides, the effects of nonradiative recombination defects can be reduced greatly because the flow of holes is confined in the center region of the emitter ridge.

  1. Electrostatics of Silicon Nano Transistor

    Directory of Open Access Journals (Sweden)

    Lalit Singh

    2011-01-01

    Full Text Available Nano Transistor represents a unique system for exploring physical phenomena pertaining to charge transport at the nano scale and is expected to play a critical role in future evolution of electronic and optoelectronic devices. This paper summarizes some of the essential electrostatics of nano Metal Oxide Semiconductor Field effect Transistor (MOSFET and their electrical properties. Though the general focus of this work is on surface potential yet the first part presents a brief discussion of the independence of charge at the top of the barrier in the channel of MOS Transistor on Drain voltage. The quantum capacitance is discussed at length. The superposition theorem is used, thereafter, to obtain an expression for self consistent potential in the channel. Finally the I-V characteristics of the device are explored using Landauer formalism. The simulated results for a device are observed to represent the realistic behaviour of the device.

  2. Passivated ambipolar black phosphorus transistors.

    Science.gov (United States)

    Yue, Dewu; Lee, Daeyeong; Jang, Young Dae; Choi, Min Sup; Nam, Hye Jin; Jung, Duk-Young; Yoo, Won Jong

    2016-07-01

    We report the first air-passivated ambipolar BP transistor formed by applying benzyl viologen, which serves as a surface charge transfer donor for BP flakes. The passivated BP devices exhibit excellent stability under both an ambient atmosphere and vacuum; their transistor performance is maintained semi-permanently. Unlike their intrinsic p-type properties, passivated BP devices present advantageous ambipolar properties with much higher electron mobility up to ∼83 cm(2) V(-1) s(-1) from 2-terminal measurement at 300 K, compared to other reported studies on n-type BP transistors. On the basis of the n-type doping effect that originated from benzyl viologen, we also systematically investigated the BP thickness dependence of our devices on electrical properties, in which we found the best electron transport performance to be attained when an ∼10 nm thick BP flake was used. PMID:27283027

  3. Growth of Gold-assisted Gallium Arsenide Nanowires on Silicon Substrates via Molecular Beam Epitaxy

    Directory of Open Access Journals (Sweden)

    Ramon M. delos Santos

    2008-06-01

    Full Text Available Gallium arsenide nanowires were grown on silicon (100 substrates by what is called the vapor-liquid-solid (VLS growth mechanism using a molecular beam epitaxy (MBE system. Good quality nanowires with surface density of approximately 108 nanowires per square centimeter were produced by utilizing gold nanoparticles, with density of 1011 nanoparticles per square centimeter, as catalysts for nanowire growth. X-ray diffraction measurements, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy revealed that the nanowires are epitaxially grown on the silicon substrates, are oriented along the [111] direction and have cubic zincblende structure.

  4. Electronic components, tubes and transistors

    CERN Document Server

    Dummer, G W A

    1965-01-01

    Electronic Components, Tubes and Transistors aims to bridge the gap between the basic measurement theory of resistance, capacitance, and inductance and the practical application of electronic components in equipments. The more practical or usage aspect of electron tubes and semiconductors is given emphasis over theory. The essential characteristics of each main type of component, tube, and transistor are summarized. This book is comprised of six chapters and begins with a discussion on the essential characteristics in terms of the parameters usually required in choosing a resistor, including s

  5. Single Electron Transistor: Applications & Problems

    Directory of Open Access Journals (Sweden)

    Om Kumar

    2010-12-01

    Full Text Available The goal of this paper is to review in brief the basic physics of nanoelectronic device single-electron transistor [SET] as well as prospective applications and problems in their applications. SET functioning based on the controllable transfer of single electrons between small conducting "islands". The device properties dominated by the quantum mechanical properties of matter and provide new characteristics coulomb oscillation, coulomb blockade that is helpful in a number of applications. SET is able to shear domain with silicon transistor in near future and enhance the device density. Recent research in SET gives new ideas which are going to revolutionize the random access memory and digital data storage technologies.

  6. Tunneling field effect transistor technology

    CERN Document Server

    Chan, Mansun

    2016-01-01

    This book provides a single-source reference to the state-of-the art in tunneling field effect transistors (TFETs). Readers will learn the TFETs physics from advanced atomistic simulations, the TFETs fabrication process and the important roles that TFETs will play in enabling integrated circuit designs for power efficiency. · Provides comprehensive reference to tunneling field effect transistors (TFETs); · Covers all aspects of TFETs, from device process to modeling and applications; · Enables design of power-efficient integrated circuits, with low power consumption TFETs.

  7. Silicon on insulator self-aligned transistors

    Science.gov (United States)

    McCarthy, Anthony M.

    2003-11-18

    A method for fabricating thin-film single-crystal silicon-on-insulator (SOI) self-aligned transistors. Standard processing of silicon substrates is used to fabricate the transistors. Physical spaces, between the source and gate, and the drain and gate, introduced by etching the polysilicon gate material, are used to provide connecting implants (bridges) which allow the transistor to perform normally. After completion of the silicon substrate processing, the silicon wafer is bonded to an insulator (glass) substrate, and the silicon substrate is removed leaving the transistors on the insulator (glass) substrate. Transistors fabricated by this method may be utilized, for example, in flat panel displays, etc.

  8. Ab initio study of the unusual thermal transport properties of boron arsenide and related materials

    Science.gov (United States)

    Broido, D. A.; Lindsay, L.; Reinecke, T. L.

    2013-12-01

    Recently, using a first principles approach, we predicted that zinc blende boron arsenide (BAs) will have an ultrahigh lattice thermal conductivity, κ, of over 2000 Wm-1K-1 at room temperature (RT), comparable to that of diamond. Here, we provide a detailed ab initio examination of phonon thermal transport in boron arsenide, contrasting its unconventional behavior with that of other related materials, including the zinc blende crystals boron nitride (BN), boron phosphide, boron antimonide, and gallium nitride (GaN). The unusual vibrational properties of BAs contribute to its weak phonon-phonon scattering and phonon-isotope scattering, which are responsible for its exceptionally high κ. The thermal conductivity of BAs has contributions from phonons with anomalously large mean free paths (˜2 μm), two to three times those of diamond and BN. This makes κ in BAs sensitive to phonon scattering from crystal boundaries. An order of magnitude smaller RT thermal conductivity in a similar material, zinc blende GaN, is connected to more separated acoustic phonon branches, larger anharmonic force constants, and a large isotope mixture on the heavy rather than the light constituent atom. The striking difference in κ for BAs and GaN demonstrates the importance of using a microscopic first principles thermal transport approach for calculating κ. BAs also has an advantageous RT coefficient of thermal expansion, which, combined with the high κ value, suggests that it is a promising material for use in thermal management applications.

  9. THE QUANTUM-WELL STRUCTURES OF SELF ELECTROOPTIC-EFFECT DEVICES AND GALLIUM-ARSENIDE

    Directory of Open Access Journals (Sweden)

    Mustafa TEMİZ

    1996-02-01

    Full Text Available Multiple quantum-well (MQW electroabsorptive self electro optic-effect devices (SEEDs are being extensively studied for use in optical switching and computing. The self electro-optic-effect devices which has quantum-well structures is a new optoelectronic technology with capability to obtain both optical inputs and outputs for Gallium-Arsenide/Aluminum Gallium-Arsenide (GaAs/AlGaAs electronic circuits. The optical inputs and outputs are based on quantum-well absorptive properties. These quantum-well structures consist of many thin layers of semiconductors materials of GaAs/AlGaAs which have emerged some important directions recently. The most important advance in the physics of these materials since the early days has been invention of the heterojunction structures which is based at present on GaAs technology. GaAs/AlGaAs structures present some important advantages to relevant band gap and index of refraction which allow to form the quantum-well structures and also to make semiconductor lasers, dedectors and waveguide optical switches.

  10. A High-Voltage Level Tolerant Transistor Circuit

    NARCIS (Netherlands)

    Annema, Anne Johan; Geelen, Godefridus Johannes Gertrudis Maria

    2001-01-01

    A high-voltage level tolerant transistor circuit, comprising a plurality of cascoded transistors, including a first transistor (T1) operatively connected to a high-voltage level node (3) and a second transistor (T2) operatively connected to a low-voltage level node (2). The first transistor (T1) con

  11. Black phosphorus nonvolatile transistor memory

    Science.gov (United States)

    Lee, Dain; Choi, Yongsuk; Hwang, Euyheon; Kang, Moon Sung; Lee, Seungwoo; Cho, Jeong Ho

    2016-04-01

    We demonstrated nanofloating gate transistor memory devices (NFGTMs) using mechanically-exfoliated few-layered black phosphorus (BP) channels and gold nanoparticle (AuNPs) charge trapping layers. The resulting BP-NFGTMs exhibited excellent memory performances, including the five-level data storage, large memory window (58.2 V), stable retention (104 s), and cyclic endurance (1000 cycles).We demonstrated nanofloating gate transistor memory devices (NFGTMs) using mechanically-exfoliated few-layered black phosphorus (BP) channels and gold nanoparticle (AuNPs) charge trapping layers. The resulting BP-NFGTMs exhibited excellent memory performances, including the five-level data storage, large memory window (58.2 V), stable retention (104 s), and cyclic endurance (1000 cycles). Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr02078j

  12. Principles of an atomtronic transistor

    Science.gov (United States)

    Caliga, Seth C.; Straatsma, Cameron J. E.; Zozulya, Alex A.; Anderson, Dana Z.

    2016-01-01

    A semiclassical formalism is used to investigate the transistor-like behavior of ultracold atoms in a triple-well potential. Atom current flows from the source well, held at fixed chemical potential and temperature, into an empty drain well. In steady-state, the gate well located between the source and drain is shown to acquire a well-defined chemical potential and temperature, which are controlled by the relative height of the barriers separating the three wells. It is shown that the gate chemical potential can exceed that of the source and have a lower temperature. In electronics terminology, the source-gate junction can be reverse-biased. As a result, the device exhibits regimes of negative resistance and transresistance, indicating the presence of gain. Given an external current input to the gate, transistor-like behavior is characterized both in terms of the current gain, which can be greater than unity, and the power output of the device.

  13. Principles of an atomtronic transistor

    CERN Document Server

    Caliga, Seth C; Zozulya, Alex A; Anderson, Dana Z

    2015-01-01

    A semiclassical formalism is used to investigate the transistor-like behavior of ultracold atoms in a triple-well potential. Atom current flows from the source well, held at fixed chemical potential and temperature, into an empty drain well. In steady-state, the gate well located between the source and drain is shown to acquire a well-defined chemical potential and temperature, which are controlled by the relative height of the barriers separating the three wells. It is shown that the gate chemical potential can exceed that of the source and have a lower temperature. In electronics terminology, the source-gate junction can be reverse-biased. As a result, the device exhibits regimes of negative resistance and transresistance, indicating the presence of gain. Given an external current input to the gate, transistor-like behavior is characterized both in terms of the current gain, which can be greater than unity, and the power output of the device.

  14. Outdoor Performance of a Thin-Film Gallium-Arsenide Photovoltaic Module

    Energy Technology Data Exchange (ETDEWEB)

    Silverman, T. J.; Deceglie, M. G.; Marion, B.; Cowley, S.; Kayes, B.; Kurtz, S.

    2013-06-01

    We deployed a 855 cm2 thin-film, single-junction gallium arsenide (GaAs) photovoltaic (PV) module outdoors. Due to its fundamentally different cell technology compared to silicon (Si), the module responds differently to outdoor conditions. On average during the test, the GaAs module produced more power when its temperature was higher. We show that its maximum-power temperature coefficient, while actually negative, is several times smaller in magnitude than that of a Si module used for comparison. The positive correlation of power with temperature in GaAs is due to temperature-correlated changes in the incident spectrum. We show that a simple correction based on precipitable water vapor (PWV) brings the photocurrent temperature coefficient into agreement with that measured by other methods and predicted by theory. The low operating temperature and small temperature coefficient of GaAs give it an energy production advantage in warm weather.

  15. Electronic structure, magnetic and superconducting properties of co-doped iron-arsenide superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Rosner, Helge; Schnelle, Walter; Nicklas, Michael; Leithe-Jasper, Andreas [MPI CPfS Dresden (Germany); Weikert, Franziska [Los Alamos National Laboratory, New Mexico (United States); HLD Dresden Rossendorf (Germany); Wosnitza, Joachim [HLD Dresden Rossendorf (Germany)

    2013-07-01

    We present a joint experimental and theoretical study of co-doped iron-arsenide superconductors of the 122 family A{sub 1-x}K{sub x}Fe{sub 2-y}T{sub y}As{sub 2} (A = Ba,Sr,Eu; T = Co,Ru,Rh). In these systems, the co-doping enables the separation of different parameters - like electron count, disorder or the specific geometry of the FeAs layer - with respect to the position of the respective compounds in the general 122 phase diagram. For a series of compounds, we investigate the relevance of the different parameters for the magnetic, thermodynamic and superconducting properties. Our experimental investigations are supported by density functional electronic structure calculations applying different approximations for doping and disorder.

  16. Ultraviolet Beam Focusing in Gallium Arsenide by Direct Excitation of Surface Plasmon Polaritons

    Directory of Open Access Journals (Sweden)

    Senfeng Lai

    2015-01-01

    Full Text Available This paper proposed that ultraviolet beam could be focused by gallium arsenide (GaAs through direct excitation of surface plasmon polaritons. Both theoretical analysis and computer simulation showed that GaAs could be a reasonably good plasmonic material in the air in the deep ultraviolet waveband. With a properly designed bull’s eye structure etched in GaAs, the ultraviolet electric field could be enhanced to as high as 20 times the incident value, and the full-width-half-maximum (FWHM of the light beam could be shrunk from ~48° to ~6°. As a plasmonic material, GaAs was compared to Ag and Al. Within the studied ultraviolet waveband, the field enhancement in GaAs was much stronger than Ag but not as high as Al.

  17. Ultrafast Relaxation Dynamics of Photo-excited Dirac Fermion in Three Dimensional Dirac Semimetal Cadmium Arsenide

    CERN Document Server

    Lu, Wei; Liu, Xuefeng; Lu, Hong; Li, Caizhen; Lai, Jiawei; Zhao, Chuan; Tian, Ye; Liao, Zhimin; Jia, Shuang; Sun, Dong

    2016-01-01

    Three dimensional (3D) Dirac semimetal exhibiting ultrahigh mobility has recently attracted enormous research interests as 3D analogues of graphene. From the prospects of future application toward electronic/optoelectronic devices with extreme performance, it is crucial to understand the relaxation dynamics of photo-excited carriers and their coupling with lattice. In this work, we report ultrafast transient reflection measurements of photo-excited carrier dynamics in cadmium arsenide (Cd3As2), which is among the most stable Dirac semimetals that have been confirmed experimentally. With low energy probe photon of 0.3 eV, photo-excited Dirac Fermions dynamics closing to Dirac point are probed. Through transient reflection measurements on bulk and nanoplate samples that have different doping intensities, and systematic probe wavelength, pump power and lattice temperature dependent measurements, the dynamical evolution of carrier distributions can be retrieved qualitatively using a two-temperature model. The pho...

  18. Methods for forming group III-V arsenide-nitride semiconductor materials

    Science.gov (United States)

    Major, Jo S. (Inventor); Welch, David F. (Inventor); Scifres, Donald R. (Inventor)

    2000-01-01

    Methods are disclosed for forming Group III--arsenide-nitride semiconductor materials. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V crystals varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V crystals can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired.

  19. Ultrafast photocurrents and terahertz radiation in gallium arsenide and carbon based nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Prechtel, Hans Leonhard

    2011-08-15

    In this thesis we developed a measurement technique based on a common pump-probe scheme and coplanar stripline circuits that enables time-resolved photocurrent measurements of contacted nanosystems with a micrometer spatial and a picosecond time resolution. The measurement technique was applied to lowtemperature grown gallium arsenide (LT-GaAs), carbon nanotubes (CNTs), graphene, and p-doped gallium arsenide (GaAs) nanowires. The various mechanisms responsible for the generation of current pulses by pulsed laser excitation were reviewed. Furthermore the propagation of the resulting electromagnetic radiation along a coplanar stripline circuit was theoretically and numerically treated. The ultrafast photocurrent response of low-temperature grown GaAs was investigated. We found two photocurrent pulses in the time-resolved response. We showed that the first pulse is consistent with a displacement current pulse. We interpreted the second pulse to result from a transport current process. We further determined the velocity of the photo-generated charge carriers to exceed the drift, thermal and quantum velocities of single charge carriers. Hereby, we interpreted the transport current pulse to stem from an electron-hole plasma excitation. We demonstrated that the photocurrent response of CNTs comprises an ultrafast displacement current and a transport current. The data suggested that the photocurrent is finally terminated by the recombination lifetime of the charge carriers. To the best of our knowledge, we presented in this thesis the first recombination lifetime measurements of contacted, suspended, CVD grown CNT networks. In addition, we studied the ultrafast photocurrent dynamics of freely suspended graphene contacted by metal electrodes. At the graphene-metal interface, we demonstrated that built-in electric fields give rise to a photocurrent with a full-width-half-maximum of a few picoseconds and that a photo-thermoelectric effect generates a current with a decay time

  20. Logarithmic current-measuring transistor circuits

    DEFF Research Database (Denmark)

    Højberg, Kristian Søe

    1967-01-01

    Describes two transistorized circuits for the logarithmic measurement of small currents suitable for nuclear reactor instrumentation. The logarithmic element is applied in the feedback path of an amplifier, and only one dual transistor is used as logarithmic diode and temperature compensating...

  1. Transistor h parameter conversion slide rule

    Science.gov (United States)

    Brantner, R. E.

    1967-01-01

    Slide rule enables the ready conversion of transistor h parameters from one form to another and reduces calculation time by a factor of 5 to 10. The scales are selected to cover all ranges of each parameter that will normally exist for any transistor, and answers are given in the correct order of magnitude, making powers-of-ten calculations unnecessary.

  2. Ultrasmall transistor-based light sources

    DEFF Research Database (Denmark)

    With Jensen, Per Baunegaard; Tavares, Luciana; Kjelstrup-Hansen, Jakob;

    Dette projekt fokuserer på at udvikle transistor baserede nanofiber lyskilder med det overordnede mål at udvikle effektive og nano skalerede flerfarvede lyskilder integreret on-chip.......Dette projekt fokuserer på at udvikle transistor baserede nanofiber lyskilder med det overordnede mål at udvikle effektive og nano skalerede flerfarvede lyskilder integreret on-chip....

  3. Ferroelectric transistor memory arrays on flexible foils

    NARCIS (Netherlands)

    Breemen, A. van; Kam, B.; Cobb, B.; Rodriguez, F.G.; Heck, G. van; Myny, K.; Marrani, A.; Vinciguerra, V.; Gelinck, G.H.

    2013-01-01

    In this paper, we successfully fabricated and operated passive matrix P(VDF-TrFE) transistor arrays, i.e. memory arrays in which no pass-transistors or other additional electronic components are used. Because of the smaller cell, a higher integration density is possible. We demonstrate arrays up to

  4. Operation and modeling of the MOS transistor

    CERN Document Server

    Tsividis, Yannis

    2011-01-01

    Operation and Modeling of the MOS Transistor has become a standard in academia and industry. Extensively revised and updated, the third edition of this highly acclaimed text provides a thorough treatment of the MOS transistor - the key element of modern microelectronic chips.

  5. In-Plane Electronic Anisotropy of Underdoped ___122___ Fe-Arsenide Superconductors Revealed by Measurements of Detwinned Single Crystals

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Ian Randal

    2012-05-08

    The parent phases of the Fe-arsenide superconductors harbor an antiferromagnetic ground state. Significantly, the Neel transition is either preceded or accompanied by a structural transition that breaks the four fold symmetry of the high-temperature lattice. Borrowing language from the field of soft condensed matter physics, this broken discrete rotational symmetry is widely referred to as an Ising nematic phase transition. Understanding the origin of this effect is a key component of a complete theoretical description of the occurrence of superconductivity in this family of compounds, motivating both theoretical and experimental investigation of the nematic transition and the associated in-plane anisotropy. Here we review recent experimental progress in determining the intrinsic in-plane electronic anisotropy as revealed by resistivity, reflectivity and ARPES measurements of detwinned single crystals of underdoped Fe arsenide superconductors in the '122' family of compounds.

  6. Charge transport in polymeric transistors

    Directory of Open Access Journals (Sweden)

    Alberto Salleo

    2007-03-01

    Full Text Available Polymeric semiconductors have attracted much attention because of their possible use as active materials in printed electronics. Thin-film transistors (TFTs are a convenient tool for studying charge-transport physics in conjugated polymers. Two families of materials are reviewed here: fluorene copolymers and polythiophenes. Because charge transport is highly anisotropic in molecular conductors, the electrical properties of conjugated polymers are strongly dependent on microstructure. Molecular weight, polydispersity, and regioregularity all affect morphology and charge-transport in these materials. Charge transport models based on microstructure are instrumental in identifying the electrical bottlenecks in these materials.

  7. Thermo-chemical properties and electrical resistivity of Zr-based arsenide chalcogenides

    Directory of Open Access Journals (Sweden)

    A. Schlechte, R. Niewa, M. Schmidt, G. Auffermann, Yu. Prots, W. Schnelle, D. Gnida, T. Cichorek, F. Steglich and R. Kniep

    2007-01-01

    Full Text Available Ternary phases in the systems Zr–As–Se and Zr–As–Te were studied using single crystals of ZrAs1.40(1Se0.50(1 and ZrAs1.60(2Te0.40(1 (PbFCl-type of structure, space group P4/nmm as well as ZrAs0.70(1Se1.30(1 and ZrAs0.75(1Te1.25(1 (NbPS-type of structure, space group Immm. The characterization covers chemical compositions, crystal structures, homogeneity ranges and electrical resistivities. At 1223 K, the Te-containing phases can be described with the general formula ZrAsxTe2−x, with 1.53(1≤x≤1.65(1 (As-rich and 0.58(1≤x≤0.75(1 (Te-rich. Both phases are located directly on the tie-line between ZrAs2 and ZrTe2, with no indication for any deviation. Similar is true for the Se-rich phase ZrAsxSe2−x with 0.70(1≤x≤0.75(1. However, the compositional range of the respective As-rich phase ZrAsx−ySe2−x (0.03(1≤y≤0.10(1; 1.42(1≤x≤1.70(1 is not located on the tie-line ZrAs2–ZrSe2, and exhibits a triangular region of existence with intrinsic deviation of the composition towards lower non-metal contents. Except for ZrAs0.75Se1.25, from the homogeneity range of the Se-rich phase, all compounds under investigation show metallic characteristics of electrical resistivity at temperatures >20 K. Related uranium and thorium arsenide selenides display a typical magnetic field-independent rise of the resistivity towards lower temperatures, which has been explained by a non-magnetic Kondo effect. However, a similar observation has been made for ZrAs1.40Se0.50, which, among the Zr-based arsenide chalcogenides, is the only system with a large concentration of intrinsic defects in the anionic substructure.

  8. High-temperature optically activated GaAs power switching for aircraft digital electronic control

    Science.gov (United States)

    Berak, J. M.; Grantham, D. H.; Swindal, J. L.; Black, J. F.; Allen, L. B.

    1983-01-01

    Gallium arsenide high-temperature devices were fabricated and assembled into an optically activated pulse-width-modulated power control for a torque motor typical of the kinds used in jet engine actuators. A bipolar heterojunction phototransistor with gallium aluminum arsenide emitter/window, a gallium arsenide junction field-effect power transistor and a gallium arsenide transient protection diode were designed and fabricated. A high-temperature fiber optic/phototransistor coupling scheme was implemented. The devices assembled into the demonstrator were successfully tested at 250 C, proving the feasibility of actuator-located switching of control power using optical signals transmitted by fibers. Assessments of the efficiency and technical merits were made for extension of this high-temperature technology to local conversion of optical power to electrical power and its control at levels useful for driving actuators. Optical power sources included in the comparisons were an infrared light-emitting diode, an injection laser diode, tungsten-halogen lamps and arc lamps. Optical-to-electrical power conversion was limited to photovoltaics located at the actuator. Impedance matching of the photovoltaic array to the load was considered over the full temperature range, -55 C to 260 C. Loss of photovoltaic efficiency at higher temperatures was taken into account. Serious losses in efficiency are: (1) in the optical source and the cooling which they may require in the assumed 125 C ambient, (2) in the decreased conversion efficiency of the gallium arsenide photovoltaic at 260 C, and (3) in impedance matching. Practical systems require improvements in these areas.

  9. Basic matrix algebra and transistor circuits

    CERN Document Server

    Zelinger, G

    1963-01-01

    Basic Matrix Algebra and Transistor Circuits deals with mastering the techniques of matrix algebra for application in transistors. This book attempts to unify fundamental subjects, such as matrix algebra, four-terminal network theory, transistor equivalent circuits, and pertinent design matters. Part I of this book focuses on basic matrix algebra of four-terminal networks, with descriptions of the different systems of matrices. This part also discusses both simple and complex network configurations and their associated transmission. This discussion is followed by the alternative methods of de

  10. Organic and polymer transistors for electronics

    Directory of Open Access Journals (Sweden)

    Ananth Dodabalapur

    2006-04-01

    Full Text Available Some of the major application areas for organic and polymeric transistors are reviewed. Organic complementary devices are promising on account of their lower power dissipation and ease of circuit design. The first organic large-scale integrated circuits have been implemented with this circuit approach. Organic transistor backplanes are ideally suited for electronic paper applications and other display schemes. Low-cost and other processing advantages, as well as improving performance, have led to organic-based radio frequency identification tag development. The chemical interaction between various organic and polymer semiconductors can be exploited in chemical and biological sensors based upon organic transistors.

  11. Transistors using crystalline silicon devices on glass

    Science.gov (United States)

    McCarthy, Anthony M.

    1995-01-01

    A method for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed.

  12. Protonic transistors from thin reflecting films

    International Nuclear Information System (INIS)

    Ionic transistors from organic and biological materials hold great promise for bioelectronics applications. Thus, much research effort has focused on optimizing the performance of these devices. Herein, we experimentally validate a straightforward strategy for enhancing the high to low current ratios of protein-based protonic transistors. Upon reducing the thickness of the transistors’ active layers, we increase their high to low current ratios 2-fold while leaving the other figures of merit unchanged. The measured ratio of 3.3 is comparable to the best values found for analogous devices. These findings underscore the importance of the active layer geometry for optimum protonic transistor functionality

  13. Monopole Charge Domain in High-Gain Gallium Arsenide Photoconductive Switches

    Institute of Scientific and Technical Information of China (English)

    施卫; 陈二柱; 张显斌; 李琦

    2002-01-01

    Considering that semi-insulating gallium arsenide photoconductive switches can be triggered into the high gain mode and no reliable theories can account for the observed transient characteristics, we propose the monopole charge domain model to explain the peculiar switching phenomena occurring in the high gain mode and we discuss the requirements for the lock-on switching. During operation on this mode, the applied field across the switch and the lock-on field are all larger than the Gunn threshold field. Our developed monopole charge domain is based on the transferred-electron effect, but the domain is only composed of large numbers of electrons piled up due to the negative differential mobility. Using the model and taking the physical mechanism of the avalanche impact ionization and recombination radiation into consideration, we interpret the typical phenomena of the lock-on effect, such as the time delay between the beginning of optical illumination and turning-on of the switch, and the conduction mechanism of the sustaining phase. Under different conditions of bias field intensity and incident light energy, the time delay of the switching is calculated. The results show that the physical mechanisms of impact ionization and recombination radiation occurring in the monopole charge domain are responsible for the lock-on switching.

  14. Nonlinear radiation response of n-doped indium antimonide and indium arsenide in intense terahertz field

    Science.gov (United States)

    Gong, Jiao-Li; Liu, Jin-Song; Chu, Zheng; Yang, Zhen-Gang; Wang, Ke-Jia; Yao, Jian-Quan

    2016-10-01

    The nonlinear radiation responses of two different n-doped bulk semiconductors: indium antimonide (InSb) and indium arsenide (InAs) in an intense terahertz (THz) field are studied by using the method of ensemble Monte Carlo (EMC) at room temperature. The results show that the radiations of two materials generate about 2-THz periodic regular spectrum distributions under a high field of 100 kV/cm at 1-THz center frequency. The center frequencies are enhanced to about 7 THz in InSb, and only 5 THz in InAs, respectively. The electron valley occupancy and the percentage of new electrons excited by impact ionization are also calculated. We find that the band nonparabolicity and impact ionization promote the generation of nonlinear high frequency radiation, while intervalley scattering has the opposite effect. Moreover, the impact ionization dominates in InSb, while impact ionization and intervalley scattering work together in InAs. These characteristics have potential applications in up-convension of THz wave and THz nonlinear frequency multiplication field. Project supported by the National Natural Science Foundation of China (Grant Nos. 11574105 and 61177095), the Natural Science Foundation of Hubei Province, China (Grant Nos. 2012FFA074 and 2013BAA002), the Wuhan Municipal Applied Basic Research Project, China (Grant No. 20140101010009), and the Fundamental Research Funds for the Central Universities, China (Grant Nos. 2013KXYQ004 and 2014ZZGH021).

  15. A stress gettering mechanism in semi-insulating, copper-contaminated gallium arsenide

    Science.gov (United States)

    Kang, Nam Soo; Zirkle, Thomas E.; Schroder, Dieter K.

    1992-07-01

    We have demonstrated a stress gettering mechanism in semi-insulating, copper-contaminated gallium arsenide (GaAs) using cathodoluminescence (CL), thermally stimulated current spectroscopy (TSC), and low temperature Fourier transform infrared spectroscopy (FTIR). Cathodoluminescence shows a local gettering effect around dislocation cores in bulk semi-insulating GaAs qualitatively. This gettering result was confirmed by low temperature FTIR data, which show absorption features resulting from the transition of electrons from the valence band to copper levels. The energy level of each absorption shoulder corresponds to the various copper levels in GaAs. After gettering, the absorption depth at each shoulder decreases. Thermally stimulated current measurements show changes after copper doping. The characteristic returns to that of uncontaminated GaAs after gettering. On the basis of these qualitative and quantitative data, we conclude that copper was gettered, and we propose a stress gettering mechanism in semi-insulating, copper-contaminated GaAs on the basis of dislocation cores acting as localized gettering sites.

  16. Interface engineering in organic transistors

    Directory of Open Access Journals (Sweden)

    Yeong Don Park

    2007-03-01

    Full Text Available Recent technological advances in organic field-effect transistors (OFETs have triggered intensive research into the molecular and mesoscale structures of organic semiconductor films that determine their charge-transport characteristics. Since the molecular structure and morphology of an organic semiconductor are largely determined by the properties of the interface between the organic film and the insulator, a great deal of research has focused on interface engineering. We review recent progress in interface engineering for the fabrication of high-performance OFETs and, in particular, engineering of the interfaces between semiconductors and insulators. The effects of interfacial characteristics on the molecular and mesoscale structures of π-conjugated molecules and the performance of OFET devices are discussed.

  17. Logic gates based on ion transistors

    Science.gov (United States)

    Tybrandt, Klas; Forchheimer, Robert; Berggren, Magnus

    2012-05-01

    Precise control over processing, transport and delivery of ionic and molecular signals is of great importance in numerous fields of life sciences. Integrated circuits based on ion transistors would be one approach to route and dispense complex chemical signal patterns to achieve such control. To date several types of ion transistors have been reported; however, only individual devices have so far been presented and most of them are not functional at physiological salt concentrations. Here we report integrated chemical logic gates based on ion bipolar junction transistors. Inverters and NAND gates of both npn type and complementary type are demonstrated. We find that complementary ion gates have higher gain and lower power consumption, as compared with the single transistor-type gates, which imitates the advantages of complementary logics found in conventional electronics. Ion inverters and NAND gates lay the groundwork for further development of solid-state chemical delivery circuits.

  18. Lateral power transistors in integrated circuits

    CERN Document Server

    Erlbacher, Tobias

    2014-01-01

    This book details and compares recent advancements in the development of novel lateral power transistors (LDMOS devices) for integrated circuits in power electronic applications. It includes the state-of-the-art concept of double-acting RESURF topologies.

  19. ARC Filters with Diamond Transistors and Buffers

    OpenAIRE

    T. Dostal

    1998-01-01

    Active RC first and second order filters using diamond transistors (voltage controlled current sources) and voltage diamond buffers (voltage controlled voltage sources) are given in this paper. Circuits are simulated and experimentally compared.

  20. Basic characteristics of the avalanche transistor

    International Nuclear Information System (INIS)

    The avalanche transistor is a useful device for a short-pulse generator of the thermionic electron-gun. However, some properties of the transistor have not been clear experimentally until now. In this report the following properties are presented: the thermal characteristics of the primary breakdown voltage, variations of the output pulse waveform according to the power supply voltage, and the estimated V-I curve of the secondary breakdown voltage. (author)

  1. Stable Transistors in Hydrogenated Amorphous Silicon

    OpenAIRE

    J. M. Shannon

    2004-01-01

    Thin-film field-effect transistors in hydrogenated amorphous silicon are notoriously unstable due to the formation of silicon dangling bond trapping states in the accumulated channel region during operation. Here, we show that by using a source-gated transistor a major improvement in stability is obtained. This occurs because the electron quasi-Fermi level is pinned near the center of the band in the active source region of the device and strong accumulation of electrons is prevented. The use...

  2. Bipolar Transistor Tester for Physics Lab

    CERN Document Server

    Baddi, Raju

    2012-01-01

    A very simple low cost bipolar transistor tester for physics lab is given. The proposed circuit not only indicates the type of transistor(NPN/PNP) but also indicates the terminals(emitter, base and collector) using simple dual colored(Red/Green) LEDs. Color diagrams of testing procedure have been given for easy following. This article describes the construction of this apparatus in all detail with schematic circuit diagram, circuit layout and constructional illustration.

  3. A single-transistor silicon synapse

    OpenAIRE

    Diorio, Chris; Hasler, Paul; Minch, Bradley A.; Mead, Carver A.

    1996-01-01

    We have developed a new floating-gate silicon MOS transistor for analog learning applications. The memory storage is nonvolatile; hot-electron injection and electron tunneling permit bidirectional memory updates. Because these updates depend on both the stored memory value and the transistor terminal voltages, the synapse can implement a learning function. We have derived a memory-update rule from the physics of the tunneling and injection processes, and have investigated synapse learning in ...

  4. Coherent detection of THz waves based on THz-induced time-resolved luminescence quenching in bulk gallium arsenide.

    Science.gov (United States)

    Chu, Zheng; Liu, Jinsong; Wang, Kejia

    2012-05-01

    A kind of photoluminescence quenching, in which the time-resolved photoluminescence is modulated by a THz pulse, has been theoretically investigated by performing the ensemble Monte Carlo method in bulk gallium arsenide (GaAs) at room temperature. The quenching ratio could reach up to 50% under a strong THz field (100  kV/cm). The range in which luminescence quenching is linearly proportional to the THz field could be over 60  kV/cm. On the basis of these results, a principle for THz modulation and coherent detection is proposed. PMID:22555695

  5. Indium gallium arsenide imaging with smaller cameras, higher-resolution arrays, and greater material sensitivity

    Science.gov (United States)

    Ettenberg, Martin H.; Cohen, Marshall J.; Brubaker, Robert M.; Lange, Michael J.; O'Grady, Matthew T.; Olsen, Gregory H.

    2002-08-01

    Indium Gallium Arsenide (InGaAs) photodiode arrays have numerous commercial, industrial, and military applications. During the past 10 years, great strides have been made in the development of these devices starting with simple 256-element linear photodiode arrays and progressing to the large 640 x 512 element area arrays now readily available. Linear arrays are offered with 512 elements on a 25 micron pitch with no defective pixels, and are used in spectroscopic monitors for wavelength division multiplexing (WDM) systems as well as in machine vision applications. A 320 x 240 solid-state array operates at room temperature, which allows development of a camera which is smaller than 25 cm3 in volume, weighs less than 100 g and uses less than 750 mW of power. Two dimensional focal plane arrays and cameras have been manufactured with detectivity, D*, greater than 1014 cm-(root)Hz/W at room temperature and have demonstrated the ability to image at night. Cameras are also critical tools for the assembly and performance monitoring of optical switches and add-drop multiplexers in the telecommunications industry. These same cameras are used for the inspection of silicon wafers and fine art, laser beam profiling, and metals manufacturing. By varying the Indium content, InGaAs photodiode arrays can be tailored to cover the entire short-wave infrared spectrum from 1.0 micron to 2.5 microns. InGaAs focal plane arrays and cameras sensitive to 2.0 micron wavelength light are now available in 320 x 240 formats.

  6. Investigation on properties of ultrafast switching in a bulk gallium arsenide avalanche semiconductor switch

    International Nuclear Information System (INIS)

    Properties of ultrafast switching in a bulk gallium arsenide (GaAs) avalanche semiconductor switch based on semi-insulating wafer, triggered by an optical pulse, were analyzed using physics-based numerical simulations. It has been demonstrated that when a voltage with amplitude of 5.2 kV is applied, after an exciting optical pulse with energy of 1 μJ arrival, the structure with thickness of 650 μm reaches a high conductivity state within 110 ps. Carriers are created due to photons absorption, and electrons and holes drift to anode and cathode terminals, respectively. Static ionizing domains appear both at anode and cathode terminals, and create impact-generated carriers which contribute to the formation of electron-hole plasma along entire channel. When the electric field in plasma region increases above the critical value (∼4 kV/cm) at which the electrons drift velocity peaks, a domain comes into being. An increase in carrier concentration due to avalanche multiplication in the domains reduces the domain width and results in the formation of an additional domain as soon as the field outside the domains increases above ∼4 kV/cm. The formation and evolution of multiple powerfully avalanching domains observed in the simulations are the physical reasons of ultrafast switching. The switch exhibits delayed breakdown with the characteristics affected by biased electric field, current density, and optical pulse energy. The dependence of threshold energy of the exciting optical pulse on the biased electric field is discussed

  7. Graphene nanopore field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Wanzhi; Skafidas, Efstratios, E-mail: sskaf@unimelb.edu.au [Centre for Neural Engineering, The University of Melbourne, 203 Bouverie Street, Carlton, Victoria 3053 (Australia); Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville, Victoria 3010 (Australia)

    2014-07-14

    Graphene holds great promise for replacing conventional Si material in field effect transistors (FETs) due to its high carrier mobility. Previously proposed graphene FETs either suffer from low ON-state current resulting from constrained channel width or require complex fabrication processes for edge-defecting or doping. Here, we propose an alternative graphene FET structure created on intrinsic metallic armchair-edged graphene nanoribbons with uniform width, where the channel region is made semiconducting by drilling a pore in the interior, and the two ends of the nanoribbon act naturally as connecting electrodes. The proposed GNP-FETs have high ON-state currents due to seamless atomic interface between the channel and electrodes and are able to be created with arbitrarily wide ribbons. In addition, the performance of GNP-FETs can be tuned by varying pore size and ribbon width. As a result, their performance and fabrication process are more predictable and controllable in comparison to schemes based on edge-defects and doping. Using first-principle transport calculations, we show that GNP-FETs can achieve competitive leakage current of ∼70 pA, subthreshold swing of ∼60 mV/decade, and significantly improved On/Off current ratios on the order of 10{sup 5} as compared with other forms of graphene FETs.

  8. High Accuracy Transistor Compact Model Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Hembree, Charles E. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Mar, Alan [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Robertson, Perry J. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    Typically, transistors are modeled by the application of calibrated nominal and range models. These models consists of differing parameter values that describe the location and the upper and lower limits of a distribution of some transistor characteristic such as current capacity. Correspond- ingly, when using this approach, high degrees of accuracy of the transistor models are not expected since the set of models is a surrogate for a statistical description of the devices. The use of these types of models describes expected performances considering the extremes of process or transistor deviations. In contrast, circuits that have very stringent accuracy requirements require modeling techniques with higher accuracy. Since these accurate models have low error in transistor descriptions, these models can be used to describe part to part variations as well as an accurate description of a single circuit instance. Thus, models that meet these stipulations also enable the calculation of quantifi- cation of margins with respect to a functional threshold and uncertainties in these margins. Given this need, new model high accuracy calibration techniques for bipolar junction transis- tors have been developed and are described in this report.

  9. Polyphosphonium-based ion bipolar junction transistors.

    Science.gov (United States)

    Gabrielsson, Erik O; Tybrandt, Klas; Berggren, Magnus

    2014-11-01

    Advancements in the field of electronics during the past few decades have inspired the use of transistors in a diversity of research fields, including biology and medicine. However, signals in living organisms are not only carried by electrons but also through fluxes of ions and biomolecules. Thus, in order to implement the transistor functionality to control biological signals, devices that can modulate currents of ions and biomolecules, i.e., ionic transistors and diodes, are needed. One successful approach for modulation of ionic currents is to use oppositely charged ion-selective membranes to form so called ion bipolar junction transistors (IBJTs). Unfortunately, overall IBJT device performance has been hindered due to the typical low mobility of ions, large geometries of the ion bipolar junction materials, and the possibility of electric field enhanced (EFE) water dissociation in the junction. Here, we introduce a novel polyphosphonium-based anion-selective material into npn-type IBJTs. The new material does not show EFE water dissociation and therefore allows for a reduction of junction length down to 2 μm, which significantly improves the switching performance of the ion transistor to 2 s. The presented improvement in speed as well the simplified design will be useful for future development of advanced iontronic circuits employing IBJTs, for example, addressable drug-delivery devices. PMID:25553192

  10. Field effect transistors for terahertz imaging

    Energy Technology Data Exchange (ETDEWEB)

    Knap, Wojciech; Coquillat, Dominique; Teppe, Frederic; Dyakonova, Nina; Nadar, Salman; El Fatimy, Abdel [Universite Montpellier 2, CNRS, UMR 5650 et URM 5207, Montpellier (France); Valusis, Gintaras; Seliuta, Dalius; Kasalynas, Irmantas [Semiconductor Physics Institute, Vilnius (Lithuania); Lusakowski, Jerzy; Karpierz, Krzysztof; Bialek, Marcin [Institute of Experimental Physics, University of Warsaw (Poland)

    2009-12-15

    Resonant frequencies of the two-dimensional plasma in field effect transistors (FETs) increase with the reduction of the channel dimensions and can reach the terahertz (THz) range for micrometer and sub-micrometer channel lengths. Nonlinearity of the gated electron gas in the transistor channel can be used for the detection of THz radiation. The possibility of tuneable narrow band detection in sub-THz and THz range, related to plasma resonances, has been demonstrated for nanometre gate length transistors at cryogenic temperatures. At room temperatures the plasma oscillations are usually strongly damped, but field effect transistors can still operate as an efficient broadband detectors in the THz range. We present an overview of experimental results on THz detection by field effect transistors made of III-V and Si materials, The material issue is discussed and first room applications of FETs for imaging at frequencies above 1 THz are demonstrated. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Phase diagram of (Li(1-x)Fe(x))OHFeSe: a bridge between iron selenide and arsenide superconductors.

    Science.gov (United States)

    Dong, Xiaoli; Zhou, Huaxue; Yang, Huaixin; Yuan, Jie; Jin, Kui; Zhou, Fang; Yuan, Dongna; Wei, Linlin; Li, Jianqi; Wang, Xinqiang; Zhang, Guangming; Zhao, Zhongxian

    2015-01-14

    Previous experimental results have shown important differences between iron selenide and arsenide superconductors which seem to suggest that the high-temperature superconductivity in these two subgroups of iron-based families may arise from different electronic ground states. Here we report the complete phase diagram of a newly synthesized superconducting (SC) system, (Li1-xFex)OHFeSe, with a structure similar to that of FeAs-based superconductors. In the non-SC samples, an antiferromagnetic (AFM) spin-density-wave (SDW) transition occurs at ∼127 K. This is the first example to demonstrate such an SDW phase in an FeSe-based superconductor system. Transmission electron microscopy shows that a well-known √5×√5 iron vacancy ordered state, resulting in an AFM order at ∼500 K in AyFe2-xSe2 (A = metal ions) superconductor systems, is absent in both non-SC and SC samples, but a unique superstructure with a modulation wave vector q = (1)/2(1,1,0), identical to that seen in the SC phase of KyFe2-xSe2, is dominant in the optimal SC sample (with an SC transition temperature Tc = 40 K). Hence, we conclude that the high-Tc superconductivity in (Li1-xFex)OHFeSe stems from the similarly weak AFM fluctuations as FeAs-based superconductors, suggesting a universal physical picture for both iron selenide and arsenide superconductors.

  12. Revealing the optoelectronic and thermoelectric properties of the Zintl quaternary arsenides ACdGeAs2 (A = K, Rb)

    International Nuclear Information System (INIS)

    Highlights: • Zintl tetragonal phase ACdGeAs2 (A = K, Rb) are chalcopyrite and semiconductors. • Their direct band gap is suitable for PV, optolectronic and thermoelectric applications. • Combination of DFT and Boltzmann transport theory is employed. • The present arsenides are found to be covalent materials. - Abstract: Chalcopyrite semiconductors have attracted much attention due to their potential implications in photovoltaic and thermoelectric applications. First principle calculations were performed to investigate the electronic, optical and thermoelectric properties of the Zintl tetragonal phase ACdGeAs2 (A = K, Rb) using the full potential linear augmented plane wave method and the Engle–Vosko GGA (EV–GGA) approximation. The present compounds are found semiconductors with direct band gap and covalent bonding character. The optical transitions are investigated via the dielectric function (real and imaginary parts) along with other related optical constants including refractive index, reflectivity and energy-loss spectrum. Combining results from DFT and Boltzmann transport theory, we reported the thermoelectric properties such as the Seebeck’s coefficient, electrical and thermal conductivity, figure of merit and power factor as function of temperatures. The present chalcopyrite Zintl quaternary arsenides deserve to be explored for their potential applications as thermoelectric materials and for photovoltaic devices

  13. Revealing the optoelectronic and thermoelectric properties of the Zintl quaternary arsenides ACdGeAs{sub 2} (A = K, Rb)

    Energy Technology Data Exchange (ETDEWEB)

    Azam, Sikander; Khan, Saleem Ayaz [New Technologies—Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic); Goumri-Said, Souraya, E-mail: Souraya.Goumri-Said@chemistry.gatech.edu [School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, GA 30332-0400 (United States)

    2015-10-15

    Highlights: • Zintl tetragonal phase ACdGeAs{sub 2} (A = K, Rb) are chalcopyrite and semiconductors. • Their direct band gap is suitable for PV, optolectronic and thermoelectric applications. • Combination of DFT and Boltzmann transport theory is employed. • The present arsenides are found to be covalent materials. - Abstract: Chalcopyrite semiconductors have attracted much attention due to their potential implications in photovoltaic and thermoelectric applications. First principle calculations were performed to investigate the electronic, optical and thermoelectric properties of the Zintl tetragonal phase ACdGeAs{sub 2} (A = K, Rb) using the full potential linear augmented plane wave method and the Engle–Vosko GGA (EV–GGA) approximation. The present compounds are found semiconductors with direct band gap and covalent bonding character. The optical transitions are investigated via the dielectric function (real and imaginary parts) along with other related optical constants including refractive index, reflectivity and energy-loss spectrum. Combining results from DFT and Boltzmann transport theory, we reported the thermoelectric properties such as the Seebeck’s coefficient, electrical and thermal conductivity, figure of merit and power factor as function of temperatures. The present chalcopyrite Zintl quaternary arsenides deserve to be explored for their potential applications as thermoelectric materials and for photovoltaic devices.

  14. Development of devices and systems of growth of gallium arsenide ingots for micro, nano electronics and photovoltaics

    Directory of Open Access Journals (Sweden)

    A. P. Oksanich

    2013-09-01

    Full Text Available Gallium arsenide is a perspective semiconductor, the need for which is constantly increasing. This is associated with the development of electronic components operating in excess of the high frequency range and development of terrestrial photovoltaics based on gallium arsenide solar cells. Increase in diameter of grown ingots leads to a deterioration in their performance, which is caused by the imperfection of growing technology. The paper presents the results of the development of systems and devices which help to improve existing technology to produce GaAs ingots and wafers with a diameter of 100 mm with the best technical parameters. Developed a system to manage growing GaAs ingot. As a sensor of diameter ingot it uses a weighting method provides a measurement error in the process of growing ± 1,0 mm. The system allows to grow GaAs ingots with an error of ± 2 mm. For the formation of temperature gradients developed thermal unit, which provides a gradient of 51 .. 53 K cm in growing of ingots with diameter of 100 mm. For adjusting the process parameters were developed measuring device of the internal stresses that are generated in the ingot during the growth of the GaAs ingot. Presented in paper technical solutions provided a silicon ingot with a diameter of 100 mm. with mobility, cm2 V-1 s-1 - 2500 ÷ 3500, the charge carrier density, cm-3 - 5x1017 ÷ 5x1018; dislocation density, cm-2 - to 8x104.

  15. Phase diagram of (Li(1-x)Fe(x))OHFeSe: a bridge between iron selenide and arsenide superconductors.

    Science.gov (United States)

    Dong, Xiaoli; Zhou, Huaxue; Yang, Huaixin; Yuan, Jie; Jin, Kui; Zhou, Fang; Yuan, Dongna; Wei, Linlin; Li, Jianqi; Wang, Xinqiang; Zhang, Guangming; Zhao, Zhongxian

    2015-01-14

    Previous experimental results have shown important differences between iron selenide and arsenide superconductors which seem to suggest that the high-temperature superconductivity in these two subgroups of iron-based families may arise from different electronic ground states. Here we report the complete phase diagram of a newly synthesized superconducting (SC) system, (Li1-xFex)OHFeSe, with a structure similar to that of FeAs-based superconductors. In the non-SC samples, an antiferromagnetic (AFM) spin-density-wave (SDW) transition occurs at ∼127 K. This is the first example to demonstrate such an SDW phase in an FeSe-based superconductor system. Transmission electron microscopy shows that a well-known √5×√5 iron vacancy ordered state, resulting in an AFM order at ∼500 K in AyFe2-xSe2 (A = metal ions) superconductor systems, is absent in both non-SC and SC samples, but a unique superstructure with a modulation wave vector q = (1)/2(1,1,0), identical to that seen in the SC phase of KyFe2-xSe2, is dominant in the optimal SC sample (with an SC transition temperature Tc = 40 K). Hence, we conclude that the high-Tc superconductivity in (Li1-xFex)OHFeSe stems from the similarly weak AFM fluctuations as FeAs-based superconductors, suggesting a universal physical picture for both iron selenide and arsenide superconductors. PMID:25532066

  16. Bipolar-FET combinational power transistors for power conversion applications

    Science.gov (United States)

    Chen, D. Y.; Chin, S. A.

    1984-01-01

    Four bipolar-FET (field-effect transistor) combinational transistor configurations are compared from the application point of view. The configurations included are FET-Darlington (cascade), emitter-open switch (cascode), parallel configuration, and FET-gated bipolar transistors (FGT).

  17. Discrete transistor measuring and matching using a solid core oven

    Science.gov (United States)

    Inkinen, M.; Mäkelä, K.; Vuorela, T.; Palovuori, K.

    2013-03-01

    This paper presents transistor measurements done at a constant temperature. The aim in this research was to develop a reliable and repeatable method for measuring and searching transistor pairs with similar parameters, as in certain applications it is advantageous to use transistors from the same production batch due to the significant variability in batches from different manufacturers. Transistor manufacturing methods are well established, but due to the large variability in tolerance, not even transistors from the same manufacturing batch have identical properties. Transistors' electrical properties are also strongly temperature-dependent. Therefore, when measuring transistor properties, the temperature must be kept constant. For the measurement process, a solid-core oven providing stable temperature was implemented. In the oven, the base-to-emitter voltage (VBE) and DC-current gain (β) of 32 transistors could be measured simultaneously. The oven's temperature was controlled with a programmable thermostat, which allowed accurate constant temperature operation. The oven is formed by a large metal block with an individual chamber for each transistor to be measured. Isolation of individual transistors and the highly thermally conductive metal core structure prevent thermal coupling between transistors. The oven enables repeatable measurements, and thus measurements between different batches are comparable. In this research study, the properties of over 5000 transistors were measured and the variance of the aforementioned properties was analyzed.

  18. Stretchable transistors with buckled carbon nanotube films as conducting channels

    Science.gov (United States)

    Arnold, Michael S; Xu, Feng

    2015-03-24

    Thin-film transistors comprising buckled films comprising carbon nanotubes as the conductive channel are provided. Also provided are methods of fabricating the transistors. The transistors, which are highly stretchable and bendable, exhibit stable performance even when operated under high tensile strains.

  19. Coherence in a cold atom photon transistor

    CERN Document Server

    Li, Weibin

    2015-01-01

    Recent experiments have realized an all-optical photon transistor using a cold atomic gas. This approach relies on electromagnetically induced transparency (EIT) in conjunction with the strong interaction among atoms excited to high-lying Rydberg states. The transistor is gated via a so-called Rydberg spinwave, in which a single Rydberg excitation is coherently shared by the whole ensemble. In its absence the incoming photon passes through the atomic ensemble by virtue of EIT while in its presence the photon is scattered rendering the atomic gas opaque. An important current challenge is to preserve the coherence of the Rydberg spinwave during the operation of the transistor, which would enable for example its coherent optical read-out and its further processing in quantum circuits. With a combined field theoretical and quantum jump approach and by employing a simple model description we investigate systematically and comprehensively how the coherence of the Rydberg spinwave is affected by photon scattering. W...

  20. Fundamentals of nanoscaled field effect transistors

    CERN Document Server

    Chaudhry, Amit

    2013-01-01

    Fundamentals of Nanoscaled Field Effect Transistors gives comprehensive coverage of the fundamental physical principles and theory behind nanoscale transistors. The specific issues that arise for nanoscale MOSFETs, such as quantum mechanical tunneling and inversion layer quantization, are fully explored. The solutions to these issues, such as high-κ technology, strained-Si technology, alternate devices structures and graphene technology are also given. Some case studies regarding the above issues and solution are also given in the book. In summary, this book: Covers the fundamental principles behind nanoelectronics/microelectronics Includes chapters devoted to solutions tackling the quantum mechanical effects occurring at nanoscale Provides some case studies to understand the issue mathematically Fundamentals of Nanoscaled Field Effect Transistors is an ideal book for researchers and undergraduate and graduate students in the field of microelectronics, nanoelectronics, and electronics.

  1. TRANSISTOR IMPLEMENTATION OF REVERSIBLE PRT GATES

    Directory of Open Access Journals (Sweden)

    RASHMI S.B,

    2011-03-01

    Full Text Available Reversible logic has emerged as one of the most important approaches for power optimization with its application in low power VLSI design. Reversible or information lossless circuits have applications in nanotechnology, digital signal processing, communication, computer graphics and cryptography. They are also a fundamental requirement in the emerging field of quantum computing. In this paper, two newoptimized universal gates are proposed. One of them has an ability to operate as a reversible half adder and half subtractor imultaneously. Another one acts only as half adder with minimum transistor count. The reversible gates are evaluated in terms of number of transistor count, critical path, garbage outputs and one to one mapping. Here transistor implementation of the proposed gates is done by using Virtuoso tool of cadence. Based on the results of the analysis, some of the trade-offs are made in the design to improve the efficiency.

  2. Characterization of solar cells for space applications. Volume 14: Electrical characteristics of Hughes liquid phase epitaxy gallium arsenide solar cells as a function of intensity, temperature and irradiation

    Science.gov (United States)

    Anspaugh, B. E.; Downing, R. G.; Miyahira, T. F.; Weiss, R. S.

    1981-01-01

    Electrical characteristics of liquid phase epitaxy, P/N gallium aluminum arsenide solar cells are presented in graphical and tabular format as a function of solar illumination intensity and temperature. The solar cells were exposed to 1 MeV electron fluences of, respectively, 0, one hundred trillion, one quadrillion, and ten quadrillion e/sq cm.

  3. EDITORIAL: Reigniting innovation in the transistor Reigniting innovation in the transistor

    Science.gov (United States)

    Demming, Anna

    2012-09-01

    Today the transistor is integral to the electronic circuitry that wires our lives. When Bardeen and Brattain first observed an amplified signal by connecting electrodes to a germanium crystal they saw that their 'semiconductor triode' could prove a useful alternative to the more cumbersome vacuum tubes used at the time [1]. But it was perhaps William Schottky who recognized the extent of the transistor's potential. A basic transistor has three or more terminals and current across one pair of terminals can switch or amplify current through another pair. Bardeen, Brattain and Schottky were jointly awarded a Nobel Prize in 1956 'for their researches on semiconductors and their discovery of the transistor effect' [2]. Since then many new forms of the transistor have been developed and understanding of the underlying properties is constantly advancing. In this issue Chen and Shih and colleagues at Taiwan National University and Drexel University report a pyroelectrics transistor. They show how a novel optothermal gating mechanism can modulate the current, allowing a range of developments in nanoscale optoelectronics and wireless devices [3]. The explosion of interest in nanoscale devices in the 1990s inspired electronics researchers to look for new systems that can act as transistors, such as carbon nanotube [4] and silicon nanowire [5] transistors. Generally these transistors function by raising and lowering an energy barrier of kBT -1, but researchers in the US and Canada have demonstrated that the quantum interference between two electronic pathways through aromatic molecules can also modulate the current flow [6]. The device has advantages for further miniaturization where energy dissipation in conventional systems may eventually cause complications. Interest in transistor technology has also led to advances in fabrication techniques for achieving high production quantities, such as printing [7]. Researchers in Florida in the US demonstrated field effect transistor

  4. Advancement in organic nanofiber based transistors

    DEFF Research Database (Denmark)

    Jensen, Per Baunegaard With; Kjelstrup-Hansen, Jakob; Tavares, Luciana;

    The focus of this project is to study the light emission from nanofiber based organic light-emitting transistors (OLETs) with the overall aim of developing efficient, nanoscale light sources with different colors integrated on-chip. The research performed here regards the fabrication and characte......The focus of this project is to study the light emission from nanofiber based organic light-emitting transistors (OLETs) with the overall aim of developing efficient, nanoscale light sources with different colors integrated on-chip. The research performed here regards the fabrication...

  5. Fundamentals of RF and microwave transistor amplifiers

    CERN Document Server

    Bahl, Inder J

    2009-01-01

    A Comprehensive and Up-to-Date Treatment of RF and Microwave Transistor Amplifiers This book provides state-of-the-art coverage of RF and microwave transistor amplifiers, including low-noise, narrowband, broadband, linear, high-power, high-efficiency, and high-voltage. Topics covered include modeling, analysis, design, packaging, and thermal and fabrication considerations. Through a unique integration of theory and practice, readers will learn to solve amplifier-related design problems ranging from matching networks to biasing and stability. More than 240 problems are included to help read

  6. Going ballistic: Graphene hot electron transistors

    Science.gov (United States)

    Vaziri, S.; Smith, A. D.; Östling, M.; Lupina, G.; Dabrowski, J.; Lippert, G.; Mehr, W.; Driussi, F.; Venica, S.; Di Lecce, V.; Gnudi, A.; König, M.; Ruhl, G.; Belete, M.; Lemme, M. C.

    2015-12-01

    This paper reviews the experimental and theoretical state of the art in ballistic hot electron transistors that utilize two-dimensional base contacts made from graphene, i.e. graphene base transistors (GBTs). Early performance predictions that indicated potential for THz operation still hold true today, even with improved models that take non-idealities into account. Experimental results clearly demonstrate the basic functionality, with on/off current switching over several orders of magnitude, but further developments are required to exploit the full potential of the GBT device family. In particular, interfaces between graphene and semiconductors or dielectrics are far from perfect and thus limit experimental device integrity, reliability and performance.

  7. Electrical Compact Modeling of Graphene Base Transistors

    Directory of Open Access Journals (Sweden)

    Sébastien Frégonèse

    2015-11-01

    Full Text Available Following the recent development of the Graphene Base Transistor (GBT, a new electrical compact model for GBT devices is proposed. The transistor model includes the quantum capacitance model to obtain a self-consistent base potential. It also uses a versatile transfer current equation to be compatible with the different possible GBT configurations and it account for high injection conditions thanks to a transit time based charge model. Finally, the developed large signal model has been implemented in Verilog-A code and can be used for simulation in a standard circuit design environment such as Cadence or ADS. This model has been verified using advanced numerical simulation.

  8. Bipolar effects in unipolar junctionless transistors

    Science.gov (United States)

    Parihar, Mukta Singh; Ghosh, Dipankar; Armstrong, G. Alastair; Yu, Ran; Razavi, Pedram; Kranti, Abhinav

    2012-08-01

    In this work, we analyze hysteresis and bipolar effects in unipolar junctionless transistors. A change in subthreshold drain current by 5 orders of magnitude is demonstrated at a drain voltage of 2.25 V in silicon junctionless transistor. Contrary to the conventional theory, increasing gate oxide thickness results in (i) a reduction of subthreshold slope (S-slope) and (ii) an increase in drain current, due to bipolar effects. The high sensitivity to film thickness in junctionless devices will be most crucial factor in achieving steep transition from ON to OFF state.

  9. Dielectric Engineered Tunnel Field-Effect Transistor

    OpenAIRE

    Ilatikhameneh, Hesameddin; Tarek A. Ameen; Klimeck, Gerhard; Appenzeller, Joerg; Rahman, Rajib

    2015-01-01

    The dielectric engineered tunnel field-effect transistor (DE-TFET) as a high performance steep transistor is proposed. In this device, a combination of high-k and low-k dielectrics results in a high electric field at the tunnel junction. As a result a record ON-current of about 1000 uA/um and a subthreshold swing (SS) below 20mV/dec are predicted for WTe2 DE-TFET. The proposed TFET works based on a homojunction channel and electrically doped contacts both of which are immune to interface stat...

  10. TWO-LAYER CRYSTAL SQUARE FOR TRANSISTORS ON A SINGLE CHIP

    OpenAIRE

    Haissam El-Aawar

    2015-01-01

    The number of transistors on a chip plays the main role in increasing the speed and performance of a microprocessor; more transistors, more speed. Increasing the number of transistors will be limited due to the design complexity and density of transistors. This article aims to introduce a new approach to increasing the number of transistors on a chip. The basic idea is to construct two-layer crystal square for transistors; this allows to increase the number of transistors two addi...

  11. A High-Voltage Level Tolerant Transistor Circuit

    OpenAIRE

    Annema, Anne Johan; Geelen, Godefridus Johannes Gertrudis Maria

    2001-01-01

    A high-voltage level tolerant transistor circuit, comprising a plurality of cascoded transistors, including a first transistor (T1) operatively connected to a high-voltage level node (3) and a second transistor (T2) operatively connected to a low-voltage level node (2). The first transistor (T1) connects to a biasing circuit (8), such as a voltage level shifter, providing a variable biasing level (V1) relative to a voltage level (VH) at the high-voltage level node (3).

  12. A comparison of the kink effect in polysilicon thin film transistors and silicon on insulator transistors

    Science.gov (United States)

    Armstrong, G. A.; Brotherton, S. D.; Ayres, J. R.

    1996-09-01

    Polysilicon thin film transistors (TFTs) differ from conventional silicon on insulator (SOI) transistors in that the TFT exhibits a fundamental gate length dependence of the voltage at which a kink occurs in the output characteristics. This difference is shown to be caused by the peak lateral electric field being strongly dependent on the doping density in an SOI transistor, but relatively insensitive to trap distribution in a TFT. Source barrier lowering which occurs in SOI transistors is absent in a TFT, where the increase in current is the result of a field redistribution along the channel. For very short gate lengths, the TFT exhibits a small pseudo-bipolar gain. Estimates of this bipolar gain can be made by simulation of TFT characteristics with and without impact ionisation. The magnitude of the gain is shown to be approximately inversely proportional to gate length.

  13. Design method for a digitally trimmable MOS transistor structure

    DEFF Research Database (Denmark)

    Ning, Feng; Bruun, Erik

    1996-01-01

    A digitally trimmable MOS transistor is a MOS transistor consisting of a drain, a source, and a main gate as well as several subgates. The transconductance of the transistor is tunabledigitally by means of connecting subgates either to the main gate or to the source terminal. In this paper......, a systematic design method for a digitally trimmable MOS transistor structure is proposed. Using the proposed method, we have designed a digitally trimmable MOS transistor structure and prototype devices were fabricated in a 2.4 micron n-well CMOS technology. Through measurements on these devices, the design...... method has been experimentally confirmed. The trimmable MOS transistor structure has been applied to a high precision current mirror to reduce mismatch in the current mirror. With the trimmable transistor structure, the mismatch can be reduced by more than one order of magnitude....

  14. High mobility and quantum well transistors design and TCAD simulation

    CERN Document Server

    Hellings, Geert

    2013-01-01

    For many decades, the semiconductor industry has miniaturized transistors, delivering increased computing power to consumers at decreased cost. However, mere transistor downsizing does no longer provide the same improvements. One interesting option to further improve transistor characteristics is to use high mobility materials such as germanium and III-V materials. However, transistors have to be redesigned in order to fully benefit from these alternative materials. High Mobility and Quantum Well Transistors: Design and TCAD Simulation investigates planar bulk Germanium pFET technology in chapters 2-4, focusing on both the fabrication of such a technology and on the process and electrical TCAD simulation. Furthermore, this book shows that Quantum Well based transistors can leverage the benefits of these alternative materials, since they confine the charge carriers to the high-mobility material using a heterostructure. The design and fabrication of one particular transistor structure - the SiGe Implant-Free Qu...

  15. Thermal transistor utilizing gas-liquid transition

    KAUST Repository

    Komatsu, Teruhisa S.

    2011-01-25

    We propose a simple thermal transistor, a device to control heat current. In order to effectively change the current, we utilize the gas-liquid transition of the heat-conducting medium (fluid) because the gas region can act as a good thermal insulator. The three terminals of the transistor are located at both ends and the center of the system, and are put into contact with distinct heat baths. The key idea is a special arrangement of the three terminals. The temperature at one end (the gate temperature) is used as an input signal to control the heat current between the center (source, hot) and another end (drain, cold). Simulating the nanoscale systems of this transistor, control of heat current is demonstrated. The heat current is effectively cut off when the gate temperature is cold and it flows normally when it is hot. By using an extended version of this transistor, we also simulate a primitive application for an inverter. © 2011 American Physical Society.

  16. A ferroelectric transparent thin-film transistor

    NARCIS (Netherlands)

    Prins, MWJ; GrosseHolz, KO; Muller, G; Cillessen, JFM; Giesbers, JB; Weening, RP; Wolf, RM

    1996-01-01

    Operation is demonstrated of a field-effect transistor made of transparant oxidic thin films, showing an intrinsic memory function due to the usage of a ferroelectric insulator. The device consists of a high mobility Sb-doped n-type SnO2 semiconductor layer, PbZr0.2Ti0.8Os3 as a ferroelectric insula

  17. Electrostatic Discharge Effects in Thin Film Transistors

    NARCIS (Netherlands)

    Golo, Natasa

    2002-01-01

    Although amorphous silicon thin film transistors (α-Si:H TFT’s) have a very low electron mobility and pronounced instabilities of their electrical characteristics, they are still very useful and they have found their place in the semiconductors industry, as they possess some very good properties: th

  18. Pixel x-ray detectors in epitaxial gallium arsenide with high-energy resolution capabilities (Fano factor experiment determination)

    International Nuclear Information System (INIS)

    Gallium Arsenide pixel detectors with an area of 170 x 320 microm2 and thickness of 5 microm, realized by molecular beam epitaxy, have been designed and tested with X- and γ rays. No significant charge trapping effects have been observed, and a charge collection efficiency of 100% has been measured. At room temperature an energy resolution of 671 eV full width at half maximum (FWHM) at 59.54 keV has been obtained, with an electronic noise of 532 eV FWHM. With the detector cooled to 243 K, the electronic noise is reduced to 373 eV FWHM, and the Kα and Kβ lines of the 55Fe spectrum can be resolved. The Fano factor for GaAs has been measured at room temperature with 59.5 keV photons yielding F = 0.12 ± 0.01

  19. Gallium arsenide integrated circuits for professional broadband applications up to 3 GHz approximately

    Science.gov (United States)

    Weidlich, H.; Pettenpaul, E.; Petz, F. A.

    1983-03-01

    A GaAs-FET-technology for the manufacture of fast GaAs broadband IC's was developed with: local ion implantation for the channel and the contact region; Si3N4 cap for annealing and in process surface protection; gold based metallizations in a modified lift-off technique; and a second Si3N4 layer on top of the metallizations for safe enclosure of the active areas and as dielectric for metal insulator metal coupling capacitors. The gains with this technology approximate those of the silicon planar technology. An antenna amplifier with 20 dB gain from 40 to 1000 MHz and a noise figure of about 4 dB was tested in different modifications with integrated load transistors and with external load inductors. The stages are cascadable without matching, so higher gains are possible. An amplifier for measurement equipment with 2 GHz bandwidth and 16 dB gain was constructed with selected antenna amplifier samples using real load resistors. Monolithic integrated differential amplifier stages show gain factors of up to 35 dB with 22 MHz 3 dB-bandwidth suitable for a 2 stage operational amplifier with dB gain and 14 MHz bandwidth.

  20. Recent progress in photoactive organic field-effect transistors

    International Nuclear Information System (INIS)

    Recent progress in photoactive organic field-effect transistors (OFETs) is reviewed. Photoactive OFETs are divided into light-emitting (LE) and light-receiving (LR) OFETs. In the first part, LE-OFETs are reviewed from the viewpoint of the evolution of device structures. Device performances have improved in the last decade with the evolution of device structures from single-layer unipolar to multi-layer ambipolar transistors. In the second part, various kinds of LR-OFETs are featured. These are categorized according to their functionalities: phototransistors, non-volatile optical memories, and photochromism-based transistors. For both, various device configurations are introduced: thin-film based transistors for practical applications, single-crystalline transistors to investigate fundamental physics, nanowires, multi-layers, and vertical transistors based on new concepts. (review)

  1. Organic Thin-Film Transistor (OTFT-Based Sensors

    Directory of Open Access Journals (Sweden)

    Daniel Elkington

    2014-04-01

    Full Text Available Organic thin film transistors have been a popular research topic in recent decades and have found applications from flexible displays to disposable sensors. In this review, we present an overview of some notable articles reporting sensing applications for organic transistors with a focus on the most recent publications. In particular, we concentrate on three main types of organic transistor-based sensors: biosensors, pressure sensors and “e-nose”/vapour sensors.

  2. Low voltage and time constant organic synapse-transistor

    OpenAIRE

    Desbief, Simon; Kyndiah, Adrica; Guerin, David; Gentili, Denis; Murgia, Mauro; Lenfant, Stéphane; Alibart, Fabien; Cramer, Tobias; Biscarini, Fabio; Vuillaume, Dominique

    2015-01-01

    We report on an artificial synapse, an organic synapse-transistor (synapstor) working at 1 volt and with a typical response time in the range 100-200 ms. This device (also called NOMFET, Nanoparticle Organic Memory Field Effect Transistor) combines a memory and a transistor effect in a single device. We demonstrate that short-term plasticity (STP), a typical synaptic behavior, is observed when stimulating the device with input spikes of 1 volt. Both significant facilitating and depressing beh...

  3. Bipolar Charge Plasma Transistor: A Novel Three Terminal Device

    OpenAIRE

    Kumar, M. Jagadesh; Nadda, Kanika

    2012-01-01

    A distinctive approach for forming a lateral Bipolar Charge Plasma Transistor (BCPT) is explored using 2-D simulations. Different metal work-function electrodes are used to induce n- and p-type charge plasma layers on undoped SOI to form the emitter, base and collector regions of a lateral NPN transistor. Electrical characteristics of the proposed device are simulated and compared with that of a conventionally doped lateral bipolar junction transistor with identical dimensions. Our simulation...

  4. Application of the Johnson criteria to graphene transistors

    International Nuclear Information System (INIS)

    For 60 years, the Johnson criteria have guided the development of materials and the materials choices for field-effect and bipolar transistor technology. Intrinsic graphene is a semi-metal, precluding transistor applications, but only under lateral bias is a gap opened and transistor action possible. This first application of the Johnson criteria to biased graphene suggests that this material will struggle to ever achieve competitive commercial applications. (fast track communication)

  5. Organic Thin-Film Transistor (OTFT)-Based Sensors

    OpenAIRE

    Daniel Elkington; Nathan Cooling; Warwick Belcher; Paul C. Dastoor; Xiaojing Zhou

    2014-01-01

    Organic thin film transistors have been a popular research topic in recent decades and have found applications from flexible displays to disposable sensors. In this review, we present an overview of some notable articles reporting sensing applications for organic transistors with a focus on the most recent publications. In particular, we concentrate on three main types of organic transistor-based sensors: biosensors, pressure sensors and “e-nose”/vapour sensors.

  6. Nonvolatile SRAM architecture using MOSFET-based spin-transistors

    OpenAIRE

    Shuto, Yusuke; Yamamoto, Shuu'ichirou; Sugahara, Satoshi

    2009-01-01

    The authors proposed and computationally analyzed nonvolatile static random access memory (NV-SRAM) architecture using metal-oxide-semiconductor field-effect transistor (MOSFET) type of spin-transistors referred to as pseudo-spin-MOSFET (PS-MOSFET). PS-MOSFET is a new circuit approach to reproduce the functions of spin-transistors, based on recently progressed magnetoresistive random access memory (MRAM) technology. The proposed NV-SRAM cell can be simply configured by connecting two PS-MOSFE...

  7. Electrical pulse burnout of transistors in intense ionizing radiation

    International Nuclear Information System (INIS)

    Tests examining possible synergistic effects of electrical pulses and ionizing radiation on transistors were performed and energy/power thresholds for transistor burnout determined. The effect of ionizing radiation on burnout thresholds was found to be minimal, indicating that electrical pulse testing in the absence of radiation produces burnout-threshold results which are applicable to IEMP studies. The conditions of ionized transistor junctions and radiation induced current surges at semiconductor device terminals are inherent in IEMP studies of electrical circuits

  8. Cylindrical-shaped nanotube field effect transistor

    KAUST Repository

    Hussain, Muhammad Mustafa

    2015-12-29

    A cylindrical-shaped nanotube FET may be manufactured on silicon (Si) substrates as a ring etched into a gate stack and filled with semiconductor material. An inner gate electrode couples to a region of the gate stack inside the inner circumference of the ring. An outer gate electrode couples to a region of the gate stack outside the outer circumference of the ring. The multi-gate cylindrical-shaped nanotube FET operates in volume inversion for ring widths below 15 nanometers. The cylindrical-shaped nanotube FET demonstrates better short channel effect (SCE) mitigation and higher performance (I.sub.on/I.sub.off) than conventional transistor devices. The cylindrical-shaped nanotube FET may also be manufactured with higher yields and cheaper costs than conventional transistors.

  9. Vertically Integrated Multiple Nanowire Field Effect Transistor.

    Science.gov (United States)

    Lee, Byung-Hyun; Kang, Min-Ho; Ahn, Dae-Chul; Park, Jun-Young; Bang, Tewook; Jeon, Seung-Bae; Hur, Jae; Lee, Dongil; Choi, Yang-Kyu

    2015-12-01

    A vertically integrated multiple channel-based field-effect transistor (FET) with the highest number of nanowires reported ever is demonstrated on a bulk silicon substrate without use of wet etching. The driving current is increased by 5-fold due to the inherent vertically stacked five-level nanowires, thus showing good feasibility of three-dimensional integration-based high performance transistor. The developed fabrication process, which is simple and reproducible, is used to create multiple stiction-free and uniformly sized nanowires with the aid of the one-route all-dry etching process (ORADEP). Furthermore, the proposed FET is revamped to create nonvolatile memory with the adoption of a charge trapping layer for enhanced practicality. Thus, this research suggests an ultimate design for the end-of-the-roadmap devices to overcome the limits of scaling. PMID:26544156

  10. Nanowire field effect transistors principles and applications

    CERN Document Server

    Jeong, Yoon-Ha

    2014-01-01

    “Nanowire Field Effect Transistor: Basic Principles and Applications” places an emphasis on the application aspects of nanowire field effect transistors (NWFET). Device physics and electronics are discussed in a compact manner, together with the p-n junction diode and MOSFET, the former as an essential element in NWFET and the latter as a general background of the FET. During this discussion, the photo-diode, solar cell, LED, LD, DRAM, flash EEPROM and sensors are highlighted to pave the way for similar applications of NWFET. Modeling is discussed in close analogy and comparison with MOSFETs. Contributors focus on processing, electrostatic discharge (ESD) and application of NWFET. This includes coverage of solar and memory cells, biological and chemical sensors, displays and atomic scale light emitting diodes. Appropriate for scientists and engineers interested in acquiring a working knowledge of NWFET as well as graduate students specializing in this subject.

  11. Performance of a spin-based insulated gate field effect transistor

    OpenAIRE

    Hall, Kimberley C.; Flatté, Michael E.

    2006-01-01

    Fundamental physical properties limiting the performance of spin field effect transistors are compared to those of ordinary (charge-based) field effect transistors. Instead of raising and lowering a barrier to current flow these spin transistors use static spin-selective barriers and gate control of spin relaxation. The different origins of transistor action lead to distinct size dependences of the power dissipation in these transistors and permit sufficiently small spin-based transistors to ...

  12. Amorphous silicon for thin-film transistors

    OpenAIRE

    Schropp, Rudolf Emmanuel Isidore

    1987-01-01

    Hydrogenated amorphous silicon (a-Si:H) has considerable potential as a semiconducting material for large-area photoelectric and photovoltaic applications. Moreover, a-Si:H thin-film transistors (TFT’s) are very well suited as switching devices in addressable liquid crystal display panels and addressable image sensor arrays, due to a new technology of low-cost, Iow-temperature processing overlarge areas. ... Zie: Abstract

  13. Fully overheated single-electron transistor.

    Science.gov (United States)

    Laakso, M A; Heikkilä, T T; Nazarov, Yuli V

    2010-05-14

    We consider the fully overheated single-electron transistor, where the heat balance is determined entirely by electron transfers. We find three distinct transport regimes corresponding to cotunneling, single-electron tunneling, and a competition between the two. We find an anomalous sensitivity to temperature fluctuations at the crossover between the two latter regimes that manifests in an exceptionally large Fano factor of current noise. PMID:20866990

  14. Electron-induced damage to NPN transistors under different fluxes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Radiation damage of NPN transistors under different fluxes with electron energy of 1.5 MeV was investigated in this article. It has been shown that when NPN transistors were irradiated to a given fluence at different electron fluxes, the shift of base current was dependent on flux. With electron flux decreasing, the shift of base current becomes larger, while collector current almost keeps constant. Thus, more degradation of NPN transistors could be caused by low-electron-flux irradiation, similar to enhanced low-dose-rate sensitivity (ELDRS) of transistors under 60Co γ-irradiation. Finally, the underlying mechanisms were discussed here.

  15. Integral optoelectronic switch based on DMOS-transistors

    Directory of Open Access Journals (Sweden)

    Politanskyy L. F.

    2008-12-01

    Full Text Available The characteristics of optoelectronic couples photodiodes-DMOS-transistor are studied in the paper. There was developed a mathematical model of volt-ampere characteristic of the given optoelectronic couple which allows to determine interrelation of its electric parameters with constructive and electrophysical parameters of photodiodes and DMOS-transistors. There was suggested a construction of integral optoelectronic switch, based on DMOS-transistors on the silicon with dielectric insulation structures (SDIS. Possible is the optic control of executive devices, connected both to the source and drain circuits of the switching transistor.

  16. Investigation of radiation stability of low-noise transistors

    International Nuclear Information System (INIS)

    The radiation effect on the noise characteristics of bipolar transistors (current, gain, base resistance and an equivalent noise charge) is studied. Several types of transistors of radiation resistance have been compared. Change in noise characteristics is shown to be caused mainly by dose dependence of a gain factor. The level of the absorbed dose, that determining the boundary of transistor KT399 application in fields of mixed radiation of accelerators has been determined experimentally. The level is 5x104 rad. For transistors KT3127, KT391 the dose level of 640 krad can be considered acceptable. 12 refs.; 3 figs

  17. Study of the structure of a thin aluminum layer on the vicinal surface of a gallium arsenide substrate by high-resolution electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lovygin, M. V., E-mail: lemi@miee.ru; Borgardt, N. I. [National Research University of Electronic Technology “MIET” (Russian Federation); Seibt, M. [Universität Göttingen, IV Physikalisches Institut (Germany); Kazakov, I. P.; Tsikunov, A. V. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

    2015-12-15

    The results of electron-microscopy studies of a thin epitaxial aluminum layer deposited onto a misoriented gallium-arsenide substrate are reported. It is established that the layer consists of differently oriented grains, whose crystal lattices are coherently conjugated with the substrate with the formation of misfit dislocations, as in the case of a layer on a singular substrate. Atomic steps on the substrate surface are visualized, and their influence on the growth of aluminum crystal grains is discussed.

  18. Organic transistors for electrophysiology (Presentation Recording)

    Science.gov (United States)

    Rivnay, Jonathan

    2015-10-01

    Efficient local transduction of biological signals is of critical importance for mapping brain activity and diagnosing pathological conditions. Traditional devices used to record electrophysiological signals are passive electrodes that require (pre)amplification with downstream electronics. Organic electrochemical transistors (OECTs) that utilize conducting polymer films as the channel have shown considerable promise as amplifying transducers due to their stability in aqueous conditions and high transconductance (>3 mS). The materials properties and physics of such transistors, however, remains largely unexplored thus limiting their potential. Here we show that the uptake of ionic charge from an electrolyte into a poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) OECT channel leads to a dependence of the effective capacitance on the entire volume of the film. Subsequently, device transconductance and time response vary with channel thickness, a defining characteristic that differentiates OECTs from field effect transistors, and provides a new degree of freedom for device engineering. Using this understanding we tailor OECTs for a variety of low (1-100 Hz) and high (1-10 kHz) frequency applications, including human electroencephalography, where high transconductance devices impart richer signal content without the need for additional amplification circuitry. We also show that the materials figure of merit OECTs is the product of hole mobility and volumetric capacitance of the channel, leading to design rules for novel high performance materials.

  19. A Heteroepitaxial Perovskite Metal-Base Transistor

    Energy Technology Data Exchange (ETDEWEB)

    Yajima, T.; Hikita, Y.; /Tokyo U.; Hwang, H.Y.; /Tokyo U. /JST, PRESTO /SLAC

    2011-08-11

    'More than Moore' captures a concept for overcoming limitations in silicon electronics by incorporating new functionalities in the constituent materials. Perovskite oxides are candidates because of their vast array of physical properties in a common structure. They also enable new electronic devices based on strongly-correlated electrons. The field effect transistor and its derivatives have been the principal oxide devices investigated thus far, but another option is available in a different geometry: if the current is perpendicular to the interface, the strong internal electric fields generated at back-to-back heterojunctions can be used for oxide electronics, analogous to bipolar transistors. Here we demonstrate a perovskite heteroepitaxial metal-base transistor operating at room temperature, enabled by interface dipole engineering. Analysis of many devices quantifies the evolution from hot-electron to permeable-base behaviour. This device provides a platform for incorporating the exotic ground states of perovskite oxides, as well as novel electronic phases at their interfaces.

  20. Studies on deep electronic levels in silicon and aluminium gallium arsenide alloys

    International Nuclear Information System (INIS)

    This thesis reports on investigations of the electrical and optical properties of deep impurity centers, related to the transition metals (TMs) Ti, Mo, W, V and Ni, in silicon. Emission rates, capture cross sections and photoionization cross sections for these impurities were determined by means of various Junction Space Charge Techniques (JSCTs), such as Deep Level Transient Spectroscopy (DLTS), dark capacitance transient and photo capacitance transient techniques. Changes in Gibbs free energy as a function of temperature were calculated for all levels. From this temperature dependence, the changes in enthalpy and entropy involved in the electron and hole transitions were deduced. The influence of high electric fields on the electronic levels in chalcogen-doped silicon were investigated using the dark capacitance transient technique. The enhancement of the electron emission from the deep centers indicated a more complex field enhancement model than the expected Poole-Frenkel effect for coulombic potentials. The possibility to determine charge states of defects using the Poole-Frenkel effect, as often suggested, is therefore questioned. The observation of a persistent decrease of the dark conductivity due to illumination in simplified AlGaAs/GaAs high Electron Mobility Transistors (HEMTs) over the temperature range 170K< T<300K is reported. A model for this peculiar behavior, based on the recombination of electrons in the two-dimensional electron gas (2DEG) located at the AlGaAs/GaAs interface with holes generated by a two-step excitation process via the deep EL2 center in the GaAs epilayer, is put forward

  1. UNJUK KERJA CATU DAYA 12 VOLT 2A DENGAN PASS ELEMENT TRANSISTOR NPN DAN PNP

    OpenAIRE

    Fathoni Fathoni

    2012-01-01

    Transistor pelewat (pass element transistor) yang dipasang pada rangkain catu daya yang menggunakan IC regulator 3  terminal adalah untuk booster arus output. Ada dua cara pemasangan transistor  pelewat  yang  umum  digunakan,  yaitu  dengan  transistor  pnp  dan  npn.  Transistor  pnp dipasang dengan basis transistor yang terhubung pada input IC regulator sedangkan transistor npn dipasang dengan basis transistor yang terhubung pada output IC regulator. Untuk mengetahui unjuk kerja dari ke...

  2. Point defects and electric compensation in gallium arsenide single crystals; Punktdefekte und elektrische Kompensation in Galliumarsenid-Einkristallen

    Energy Technology Data Exchange (ETDEWEB)

    Kretzer, Ulrich

    2007-12-10

    In the present thesis the point-defect budget of gallium arsenide single crystals with different dopings is studied. It is shown, in which way the concentration of the single point defects depende on the concentration of the dopants, the stoichiometry deviation, and the position of the Fermi level. For this serve the results of the measurement-technical characterization of a large number of samples, in the fabrication of which these parameters were directedly varied. The main topic of this thesis lies in the development of models, which allow a quantitative description of the experimentally studied electrical and optical properties of gallium arsenide single crystals starting from the point-defect concentrations. Because from point defects charge carriers can be set free, their concentration determines essentially the charge-carrier concentration in the bands. In the ionized state point defects act as scattering centers for free charge carriers and influence by this the drift mobility of the charge carriers. A thermodynamic modeling of the point-defect formation yields statements on the equilibrium concentrations of the point defects in dependence on dopant concentration and stoichiometry deviation. It is show that the electrical properties of the crystals observed at room temperature result from the kinetic suppression of processes, via which the adjustment of a thermodynamic equilibrium between the point defects is mediated. [German] In der vorliegenden Arbeit wird der Punktdefekthaushalt von Galliumarsenid-Einkristallen mit unterschiedlichen Dotierungen untersucht. Es wird gezeigt, in welcher Weise die Konzentration der einzelnen Punktdefekte von der Konzentration der Dotierstoffe, der Stoechiometrieabweichung und der Lage des Ferminiveaus abhaengen. Dazu dienen die Ergebnisse der messtechnischen Charakterisierung einer grossen Anzahl von Proben, bei deren Herstellung diese Parameter gezielt variiert wurden. Der Schwerpunkt der Arbeit liegt in der Entwicklung

  3. Low-Inductance Wiring For Parallel Switching Transistors

    Science.gov (United States)

    Veatch, M. S.; Landis, D. M.

    1990-01-01

    Simple configuration for wiring of multiple parallel-connected switching transistors minimizes stray wiring inductance while providing for use of balancing transformers, which equalize currents in transistors. Currents balanced on twisted pairs of wires. Because twisted pairs carry both "hot-side" and return currents, this configuration has relatively low inductance.

  4. Transistor bonding pad configuration for uniform injection and low inductance

    Science.gov (United States)

    Jacobson, D. S.

    1970-01-01

    Modification of process for fabricating transistors, which comprises a metallization-pattern design for emitter and base areas together with a double bonding configuration for each emitter and base-bonding lead, improves uniformity of carrier injection in transistors and of reducing lead inductances at base-emitter terminals.

  5. Single-event burnout of epitaxial bipolar transistors

    Energy Technology Data Exchange (ETDEWEB)

    Kuboyama, S.; Sugimoto, K.; Shugyo, S.; Matsuda, S. [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan); Hirao, T. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan)

    1998-12-01

    Single-Event Burnout (SEB) of bipolar junction transistors (BJTs) has been observed nondestructively. It was revealed that all the NPN BJTs, including small signal transistors, with thinner epitaxial layers were inherently susceptible to the SEB phenomenon. It was demonstrated that several design parameters of BJTs were responsible for SEB susceptibility. Additionally, destructive and nondestructive modes of SEB were identified.

  6. Single-event burnout of epitaxial bipolar transistors

    Energy Technology Data Exchange (ETDEWEB)

    Kuboyama, Satoshi; Sugimoto, Kenji; Matsuda, Sumio [National Space Development Agency of Japan, Ysukuba, Ibaraki (Japan); Hirao, Toshio

    1998-10-01

    Single-event burnout (SEB) of bipolar junction transistors (BJTs) has been observed nondestructively. It was revealed that all the NPN BJTs including small signal transistors with thinner epitaxial layer were inherently susceptible to the SEB phenomenon. It was demonstrated that several design parameters of BJTs were responsible for SEB susceptibility. Additionally, destructive and nondestructive modes of SEB were identified. (author)

  7. Ambipolar MoS2 Thin Flake Transistors

    NARCIS (Netherlands)

    Zhang, Yijin; Ye, Jianting; Matsuhashi, Yusuke; Iwasa, Yoshihiro

    2012-01-01

    Field effect transistors (FETs) made of thin flake single crystals isolated from layered materials have attracted growing interest since the success of graphene. Here, we report the fabrication of an electric double layer transistor (EDLT, a FET gated by ionic liquids) using a thin flake of MoS2, a

  8. On the 50th Anniversary of the Transistor

    DEFF Research Database (Denmark)

    Stassen, Flemming

    1997-01-01

    This paper celebrates the 50th anniversary of the invention of the bipolar transistor in 1947. Combined with the inventions of integration and planar technology, the invention of the transistor marks the beginning of a period of unprecedented growth, the industrialization of electronics....

  9. Outlook and Emerging Semiconducting Materials for Ambipolar Transistors

    NARCIS (Netherlands)

    Bisri, Satria Zulkarnaen; Piliego, Claudia; Gao, Jia; Loi, Maria Antonietta

    2014-01-01

    Ambipolar or bipolar transistors are transistors in which both holes and electrons are mobile inside the conducting channel. This device allows switching among several states: the hole-dominated on-state, the off-state, and the electron-dominated on-state. In the past year, it has attracted great in

  10. The Complete Semiconductor Transistor and Its Incomplete Forms

    Institute of Scientific and Technical Information of China (English)

    Jie Binbin; Sah Chih-Tang

    2009-01-01

    This paper describes the definition of the complete transistor. For semiconductor devices, the complete transistor is always bipolar, namely, its electrical characteristics contain both electron and hole currents controlled by their spatial charge distributions. Partially complete or incomplete transistors, via coined names or/and designed physical geometries, included the 1949 Shockley p/n junction transistor (later called Bipolar Junction Transistor,BJT), the 1952 Shockley unipolar 'field-effect' transistor (FET, later called the p/n Junction Gate FET or JGFET), as well as the field-effect transistors introduced by later investigators. Similarities between the surface-channel MOS-gate FET (MOSFET) and the volume-channel BJT are illustrated. The bipolar currents, identified by us in a recent nanometer FET with 2-MOS-gates on thin and nearly pure silicon base, led us to the recognition of the physical makeup and electrical current and charge compositions of a complete transistor and its extension to other three or more terminal signal processing devices, and also the importance of the terminal contacts.

  11. The Smallest Transistor-Based Nonautonomous Chaotic Circuit

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamasevicius, Arunas

    2005-01-01

    A nonautonomous chaotic circuit based on one transistor, two capacitors, and two resistors is described. The mechanism behind the chaotic performance is based on “disturbance of integration.” The forward part and the reverse part of the bipolar transistor are “fighting” about the charging...

  12. Fabrication and characterization of advanced Organic Thin Film Transistors

    OpenAIRE

    Scaldaferri, Rossana

    2009-01-01

    The thesis aims to the development of Organic Thin Film Transistors and more complex devices based on organic materials. The experimental work demonstrates the possibility to manufacture transistors and more complex circuits with innovative polymers and technologies, leading to an experimental validation of the possibility to realize all-organic devices.

  13. Method for double-sided processing of thin film transistors

    Science.gov (United States)

    Yuan, Hao-Chih; Wang, Guogong; Eriksson, Mark A.; Evans, Paul G.; Lagally, Max G.; Ma, Zhenqiang

    2008-04-08

    This invention provides methods for fabricating thin film electronic devices with both front- and backside processing capabilities. Using these methods, high temperature processing steps may be carried out during both frontside and backside processing. The methods are well-suited for fabricating back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

  14. The Ebers-Moll model for magnetic bipolar transistors

    OpenAIRE

    Fabian, J.; Zutic, I.

    2004-01-01

    The equivalent electrical circuit of the Ebers-Moll type is introduced for magnetic bipolar transistors. In addition to conventional diodes and current sources, the new circuit comprises two novel elements due to spin-charge coupling. A classification scheme of the operating modes of magnetic bipolar transistors in the low bias regime is presented.

  15. Flexible Proton-Gated Oxide Synaptic Transistors on Si Membrane.

    Science.gov (United States)

    Zhu, Li Qiang; Wan, Chang Jin; Gao, Ping Qi; Liu, Yang Hui; Xiao, Hui; Ye, Ji Chun; Wan, Qing

    2016-08-24

    Ion-conducting materials have received considerable attention for their applications in fuel cells, electrochemical devices, and sensors. Here, flexible indium zinc oxide (InZnO) synaptic transistors with multiple presynaptic inputs gated by proton-conducting phosphorosilicate glass-based electrolyte films are fabricated on ultrathin Si membranes. Transient characteristics of the proton gated InZnO synaptic transistors are investigated, indicating stable proton-gating behaviors. Short-term synaptic plasticities are mimicked on the proposed proton-gated synaptic transistors. Furthermore, synaptic integration regulations are mimicked on the proposed synaptic transistor networks. Spiking logic modulations are realized based on the transition between superlinear and sublinear synaptic integration. The multigates coupled flexible proton-gated oxide synaptic transistors may be interesting for neuroinspired platforms with sophisticated spatiotemporal information processing. PMID:27471861

  16. Kondo Effect in a Single Electron Transistor

    Science.gov (United States)

    Goldhaber-Gordon, David

    1998-03-01

    When a field-effect transistor is made very small, and electrons in the channel are separated from those in the leads by tunnel junctions, the transistor turns on and off every time an extra electron is added to the channel. The droplet of electrons confined in the channel of such a single-electron transistor (SET) interacts with electrons in the leads. This is in close analogy to an impurity atom interacting with the delocalized electrons in a metal, the traditional system for studying the Kondo effect.(Y. Meir, N.S. Wingreen, and P.A. Lee. PRL) 70, 2601 (1993) I will discuss measurements on a new generation of SETs that display all the aspects of the Kondo effect:(D. Goldhaber-Gordon, Hadas Shtrikman, D. Mahalu, D. Abusch-Magder, U. Meirav, and M.A. Kastner. To be published in Nature). a spin singlet forms between a localized electron in the channel and delocalized electrons in the leads, causing an enhancement of the zero-bias conductance, when the number of electrons on the artificial atom is odd but not when it is even. The system can be studied out of equilibrium by applying a voltage between the two leads, an impossible procedure in bulk Kondo systems. The spin singlet is altered by applying such a voltage or a magnetic field or by increasing the temperature, all in ways that agree with predictions. In addition, the tunability of an SET allows study of the system over a range of parameters not easily accessible to previous calculations or experiments.

  17. Non-local exchange correlation functionals impact on the structural, electronic and optical properties of III-V arsenides

    KAUST Repository

    Anua, N. Najwa

    2013-08-20

    Exchange correlation (XC) energy functionals play a vital role in the efficiency of density functional theory (DFT) calculations, more soundly in the calculation of fundamental electronic energy bandgap. In the present DFT study of III-arsenides, we investigate the implications of XC-energy functional and corresponding potential on the structural, electronic and optical properties of XAs (X = B, Al, Ga, In). Firstly we report and discuss the optimized structural lattice parameters and the band gap calculations performed within different non-local XC functionals as implemented in the DFT-packages: WIEN2k, CASTEP and SIESTA. These packages are representative of the available code in ab initio studies. We employed the LDA, GGA-PBE, GGA-WC and mBJ-LDA using WIEN2k. In CASTEP, we employed the hybrid functional, sX-LDA. Furthermore LDA, GGA-PBE and meta-GGA were employed using SIESTA code. Our results point to GGA-WC as a more appropriate approximation for the calculations of structural parameters. However our electronic bandstructure calculations at the level of mBJ-LDA potential show considerable improvements over the other XC functionals, even the sX-LDA hybrid functional. We report also the optical properties within mBJ potential, which show a nice agreement with the experimental measurements in addition to other theoretical results. © 2013 IOP Publishing Ltd.

  18. CO{sub 2} laser-based dispersion interferometer utilizing orientation-patterned gallium arsenide for plasma density measurements

    Energy Technology Data Exchange (ETDEWEB)

    Bamford, D. J.; Cummings, E. A.; Panasenko, D. [Physical Sciences Inc., 6652 Owens Drive, Pleasanton, California 94588 (United States); Fenner, D. B.; Hensley, J. M. [Physical Sciences Inc., 20 New England Business Center, Andover, Massachusetts 01810 (United States); Boivin, R. L.; Carlstrom, T. N.; Van Zeeland, M. A. [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)

    2013-09-15

    A dispersion interferometer based on the second-harmonic generation of a carbon dioxide laser in orientation-patterned gallium arsenide has been developed for measuring electron density in plasmas. The interferometer includes two nonlinear optical crystals placed on opposite sides of the plasma. This instrument has been used to measure electron line densities in a pulsed radio-frequency generated argon plasma. A simple phase-extraction technique based on combining measurements from two successive pulses of the plasma has been used. The noise-equivalent line density was measured to be 1.7 × 10{sup 17} m{sup −2} in a detection bandwidth of 950 kHz. One of the orientation-patterned crystals produced 13 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 13 W of peak power. Two crystals arranged sequentially produced 58 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 37 W of peak power.

  19. A final report for Gallium arsenide P-I-N detectors for high-sensitivity imaging of thermal neutrons

    CERN Document Server

    Vernon, S M

    1999-01-01

    This SBIR Phase I developed neutron detectors made FR-om gallium arsenide (GaAs) p-type/ intrinsic/n-type (P-I-N) diodes grown by metalorganic chemical vapor deposition (MOCVD) onto semi-insulating (S1) bulk GaAs wafers. A layer of isotonically enriched boron-10 evaporated onto the FR-ont surface serves to convert incoming neutrons into lithium ions and a 1.47 MeV alpha particle which creates electron-hole pairs that are detected by the GaAs diode. Various thicknesses of ''intrinsic'' (I) undoped GaAs were tested, as was use of a back-surface field (BSF) formed FR-om a layer of Al sub x Ga sub 1 sub - sub x As. Schottky-barrier diodes formed FR-om the same structures without the p+ GaAs top layer were tested as a comparison. After mesa etching and application of contacts, devices were tested in visible light before application of the boron coating. Internal quantum efficiency (IQE) of the best diode near the GaAs bandedge is over 90%. The lowest dark current measured is 1 x 10 sup - sup 1 sup 2 amps at -1 V o...

  20. The effect of hydrostatic pressure on the physical properties of magnesium arsenide in cubic and hexagonal phases

    Science.gov (United States)

    Mokhtari, Ali; Sedighi, Matin

    2010-04-01

    Full potential-linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT) was applied to study the structural and electronic properties of the magnesium arsenide in both cubic and hexagonal phases. The exchange-correlation functional was approximated as a generalized gradient functional introduced by Perdew-Burke-Ernzerhof (GGA96) and Engel-Vosko (EV-GGA). The lattice parameters, bulk modulus and its pressure derivative, cohesive energy, band structures and effective mass of electrons and holes (EME and EMH) were obtained and compared to the available experimental and theoretical results. A phase transition was predicted at pressure of about 1.63 GPa from the cubic to the hexagonal phase. The effect of hydrostatic pressure on the behavior of the electronic properties such as band gap, valence bandwidths, anti-symmetry gap (the energy gap between two parts of the valence bands), EME and EMH were investigated using both GGA96 and EV-GGA methods. High applied pressure can decrease (increase) the holes mobility of cubic (hexagonal) phase of this compound.

  1. Development of a unique laboratory standard: Indium gallium arsenide detector for the 500-1700 nm spectral region

    Science.gov (United States)

    1987-01-01

    A planar (5 mm diameter) indium gallium arsenide detector having a high (greater than 50 pct) quantum efficiency from the visible into the infrared spectrum (500 to 1700 nm) was fabricated. Quantum efficiencies as high as 37 pct at 510 nm, 58 pct at 820 nm and 62 pct at 1300 nm and 1550 nm were measured. A planar InP/InGaAs detector structure was also fabricated using vapor phase epitaxy to grow device structures with 0, 0.2, 0.4 and 0.6 micrometer thick InP caps. Quantum efficiency was studied as a function of cap thickness. Conventional detector structures were also used by completely etching off the InP cap after zinc diffusion. Calibrated quantum efficiencies were measured. Best results were obtained with devices whose caps were completely removed by etching. Certain problems still remain with these detectors including non-uniform shunt resistance, reproducibility, contact resistance and narrow band anti-reflection coatings.

  2. High-performance organic/inorganic hybrid heterojunction based on Gallium Arsenide (GaAs) substrates and a conjugated polymer

    Science.gov (United States)

    Jameel, D. A.; Felix, J. F.; Aziz, M.; Al Saqri, N.; Taylor, D.; de Azevedo, W. M.; da Silva, E. F.; Albalawi, H.; Alghamdi, H.; Al Mashary, F.; Henini, M.

    2015-12-01

    In this paper, we present an extensive study of the electrical properties of organic-inorganic hybrid heterojunctions. Polyaniline (PANI) thin films were deposited by a very simple technique on (1 0 0) and (3 1 1)B n-type Gallium Arsenide (GaAs) substrates to fabricate hybrid devices with excellent electrical properties. The hybrid devices were electrically characterized using current-voltage (I-V), capacitance-voltage (C-V) and deep level transient spectroscopy (DLTS) measurements in the temperature range 20-440 K. The analysis of I-V characteristics based on the thermionic emission mechanism has shown a decrease of the barrier height and an increase of the ideality factor at lower temperatures for both hybrid devices. The interface states were analyzed by series resistance obtained using the C-G-V methods. The interface state density (Dit) of PANI/(1 0 0) GaAs devices is approximately one order of magnitude higher than that of PANI/(3 1 1)B GaAs devices. This behaviour is attributed to the effect of crystallographic orientation of the substrates, and was confirmed by DLTS results as well. Additionally, the devices show excellent air stability, with rectification ratio values almost unaltered after two years of storage under ambient conditions, making the polyaniline an interesting conductor polymer for future devices applications.

  3. A novel three-jet microreactor for localized metal-organic chemical vapour deposition of gallium arsenide: design and simulation

    Science.gov (United States)

    Konakov, S. A.; Krzhizhanovskaya, V. V.

    2016-08-01

    We present a novel three-jet microreactor design for localized deposition of gallium arsenide (GaAs) by low-pressure Metal-Organic Chemical Vapour Deposition (MOCVD) for semiconductor devices, microelectronics and solar cells. Our approach is advantageous compared to the standard lithography and etching technology, since it preserves the nanostructure of the deposited material, it is less time-consuming and less expensive. We designed two versions of reactor geometry with a 10-micron central microchannel for precursor supply and with two side jets of a dilutant to control the deposition area. To aid future experiments, we performed computational modeling of a simplified-geometry (twodimensional axisymmetric) microreactor, based on Navier-Stokes equations for a laminar flow of chemically reacting gas mixture of Ga(CH3)3-AsH3-H2. Simulation results show that we can achieve a high-rate deposition (over 0.3 μm/min) on a small area (less than 30 μm diameter). This technology can be used in material production for microelectronics, optoelectronics, photovoltaics, solar cells, etc.

  4. Carbon Based Transistors and Nanoelectronic Devices

    Science.gov (United States)

    Rouhi, Nima

    Carbon based materials (carbon nanotube and graphene) has been extensively researched during the past decade as one of the promising materials to be used in high performance device technology. In long term it is thought that they may replace digital and/or analog electronic devices, due to their size, near-ballistic transport, and high stability. However, a more realistic point of insertion into market may be the printed nanoelectronic circuits and sensors. These applications include printed circuits for flexible electronics and displays, large-scale bendable electrical contacts, bio-membranes and bio sensors, RFID tags, etc. In order to obtain high performance thin film transistors (as the basic building block of electronic circuits) one should be able to manufacture dense arrays of all semiconducting nanotubes. Besides, graphene synthesize and transfer technology is in its infancy and there is plenty of room to improve the current techniques. To realize the performance of nanotube and graphene films in such systems, we need to economically fabricate large-scale devices based on these materials. Following that the performance control over such devices should also be considered for future design variations for broad range of applications. Here we have first investigated carbon nanotube ink as the base material for our devices. The primary ink used consisted of both metallic and semiconducting nanotubes which resulted in networks suitable for moderate-resistivity electrical connections (such as interconnects) and rfmatching circuits. Next, purified all-semiconducting nanotube ink was used to fabricate waferscale, high performance (high mobility, and high on/off ratio) thin film transistors for printed electronic applications. The parameters affecting device performance were studied in detail to establish a roadmap for the future of purified nanotube ink printed thin film transistors. The trade of between mobility and on/off ratio of such devices was studied and the

  5. Hysteresis modeling in graphene field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Winters, M.; Rorsman, N. [Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412-96 Göteborg (Sweden); Sveinbjörnsson, E. Ö. [Science Institute, University of Iceland, IS-107 Reykjavik (Iceland)

    2015-02-21

    Graphene field effect transistors with an Al{sub 2}O{sub 3} gate dielectric are fabricated on H-intercalated bilayer graphene grown on semi-insulating 4H-SiC by chemical vapour deposition. DC measurements of the gate voltage v{sub g} versus the drain current i{sub d} reveal a severe hysteresis of clockwise orientation. A capacitive model is used to derive the relationship between the applied gate voltage and the Fermi energy. The electron transport equations are then used to calculate the drain current for a given applied gate voltage. The hysteresis in measured data is then modeled via a modified Preisach kernel.

  6. Printed shadow masks for organic transistors

    Science.gov (United States)

    Noguchi, Yoshiaki; Sekitani, Tsuyoshi; Someya, Takao

    2007-09-01

    We have manufactured organic field-effect transistors by using shadow masks that are patterned by a screen printing system. The 50-nm-thick pentacene layer is sublimed as a channel in the vacuum system through the shadow mask on the base film with a multilayer patterned by ink-jet. After the deposition of the pentacene layer, the shadow mask is peeled off from the base film without any mechanical damages to the lower structures. The mobility in the saturation regime is 0.4cm2/Vs and the on-off ratio exceeds 105.

  7. Drain Voltage Scaling in Carbon Nanotube Transistors

    OpenAIRE

    Radosavljevic, M.; Heinze, S.; Tersoff, J.; Avouris, Ph.

    2003-01-01

    While decreasing the oxide thickness in carbon nanotube field-effect transistors (CNFETs) improves the turn-on behavior, we demonstrate that this also requires scaling the range of the drain voltage. This scaling is needed to avoid an exponential increase in Off-current with drain voltage, due to modulation of the Schottky barriers at both the source and drain contact. We illustrate this with results for bottom-gated ambipolar CNFETs with oxides of 2 and 5 nm, and give an explicit scaling rul...

  8. Gate engineered performance of single molecular transistor

    Science.gov (United States)

    Ray, S. J.

    2016-05-01

    The operation, performance and electrostatics of multigated Single Molecular Transistor (SMT) devices are investigated using first-principles based density functional theory calculations for planar (pentacene) and non-planar (sucrose) molecules as islands. It has been found that the incorporation of larger numbers of gates allows enhanced electrostatic control in the SMT operation which has been quantified from the energy calculations and estimation of the gate capacitances. The effect of multiple gates is more dominant for a non-planar molecule than a planar molecule within an SMT which indicates the usefulness of such multi-gate architectures for future nanoelectronic devices.

  9. Microwave Enhanced Cotunneling in SET Transistors

    DEFF Research Database (Denmark)

    Manscher, Martin; Savolainen, M.; Mygind, Jesper

    2003-01-01

    Cotunneling in single electron tunneling (SET) devices is an error process which may severely limit their electronic and metrologic applications. Here is presented an experimental investigation of the theory for adiabatic enhancement of cotunneling by coherent microwaves. Cotunneling in SET...... transistors has been measured as function of temperature, gate voltage, frequency, and applied microwave power. At low temperatures and applied power levels, including also sequential tunneling, the results can be made consistent with theory using the unknown damping in the microwave line as the only free...

  10. Dose Rate Effects in Linear Bipolar Transistors

    Science.gov (United States)

    Johnston, Allan; Swimm, Randall; Harris, R. D.; Thorbourn, Dennis

    2011-01-01

    Dose rate effects are examined in linear bipolar transistors at high and low dose rates. At high dose rates, approximately 50% of the damage anneals at room temperature, even though these devices exhibit enhanced damage at low dose rate. The unexpected recovery of a significant fraction of the damage after tests at high dose rate requires changes in existing test standards. Tests at low temperature with a one-second radiation pulse width show that damage continues to increase for more than 3000 seconds afterward, consistent with predictions of the CTRW model for oxides with a thickness of 700 nm.

  11. Indium arsenide as a material for biological applications: Assessment of surface modifications, toxicity, and biocompatibility

    Science.gov (United States)

    Jewett, Scott A.

    III-V semiconductors such as InAs have recently been employed in a variety of applications where the electronic and optical characteristics of traditional, silicon-based materials are inadequate. InAs has a narrow band gap and very high electron mobility in the near-surface region, which makes it very attractive for high performance transistors, optical applications, and chemical sensing. However, InAs forms an unstable surface oxide layer in ambient conditions, which can corrode over time and leach toxic indium and arsenic components. Current research has gone into making InAs more attractive for biological applications through passivation of the surface by adlayer adsorption. In particular, wet-chemical methods are current routes of exploration due to their simplicity, low cost, and flexibility in the type of passivating molecule. This dissertation focuses on surface modifications of InAs using wet-chemical methods in order to further its use in biological applications. First, the adsorption of collagen binding peptides and mixed peptide/thiol adlayers onto InAs was assessed. X-ray photoelectron spectroscopy (XPS) along with atomic force microscopy (AFM) data suggested that the peptides successfully adsorbed onto InAs, but were only able to block oxide regrowth to a relatively low extent. This low passivation ability is due to the lack of covalent bonds of the peptide to InAs, which are necessary to effectively block oxide regrowth. The addition of a thiol, in the form of mixed peptide/thiol adlayers greatly enhanced passivation of InAs while maintaining peptide presence on the surface. Thiols form tight, covalent bonds with InAs, which prevents oxide regrowth. The presence of the collagen-binding peptide on the surface opens the door to subsequent modification with collagen or polyelectrolyte-based adlayers. Next, the stability and toxicity of modified InAs substrates were determined using inductively coupled plasma mass spectrometry (ICP-MS) and zebrafish

  12. UNJUK KERJA CATU DAYA 12 VOLT 2A DENGAN PASS ELEMENT TRANSISTOR NPN DAN PNP

    Directory of Open Access Journals (Sweden)

    Fathoni Fathoni

    2012-03-01

    Hasil  pengujian menunjukkan  bahwa catu daya  yang menggunakan  transistor  pelewat  jenis pnp lebih bagus regulasi bebannya dibanding transistor npn, yaitu 0,827 % dibandinng 2,149 %. Saat kondisi hubung singkat, berlaku sebaliknya, yaitu suhu heat sink transistor npn serta IC regulatornya lebih baik dibanding transistor pnp serta IC regulatornya, yaitu 52 °C dan 47 °C   untuk transistor npn dan IC regulatornya dibanding 58°dan 63 °C untuk transistor pnp dan IC regulatornya. Kata kunci: Hubung-singkat, IC regulator, regulasi-beban, transistor-pelewat

  13. Carbon nanotubes field effect transistors biosensors

    Directory of Open Access Journals (Sweden)

    M.P. Marco

    2012-03-01

    Full Text Available Carbon nanotube transistor arrays (CNTFETs wereused as biosensors to detect DNA hybridization andto recognize two anabolic steroids, stanozolol (Stzand methylboldenone (MB. Single strand DNA andantibodies specific for STz and MB were immobilizedon the carbon nanotubes (CNTs in situ in the deviceusing two different approaches: direct noncovalentbonding of antibodies to the devices and covalentlytrough a polymer previously attached to theCNTFETs. A new approach to ensure specificadsorption of the biomolecules to the nanotubeswas developed. The polymer poly(methylmethacrylate0.8-co-poly (ethyleneglycolmethacrylate0.8-co-N-succinimidyl methacrylate0.1was synthesized and bonded noncovalently to thenanotube. Aminated single-strand DNA or antibodiesspecific for Stz and MB were then attached covalentlyto the polymer. Statistically significant changes wereobserved in key transistor parameters for both DNAhybridization and steroids recognition. Regardingthe detection mechanism, in addition to chargetransfer, Schottky barrier, SB, modification, andscattering potential reported by other authors, anelectron/hole trapping mechanism leading tohysteresis modification has been determined. Thepresence of polymer seems to hinder the modulationof the electrode-CNT contact.

  14. Coherent Matterwave Emission from an Atomtronic Transistor

    Science.gov (United States)

    Straatsma, Cameron; Anderson, Dana

    2016-05-01

    We investigate matterwave emission from a triple-well ``transistor'' atomic potential consisting of a ``source'' well treated as a reservoir having fixed chemical potential and temperature, a narrow ``gate'' well, and a ``drain'' well coupled to the vacuum. The ground state of the gate well is occupied by a Bose-Einstein condensate having large chemical potential along with the first excited state of the potential. These lower states are coupled to the two highest lying bound states lying near the top of the barriers separating the gate from the other two wells. We show that the energy level separations of the two lower states and the two upper states can be made degenerate by design of the Gaussian barrier widths and separation. When degenerate, the two pairs of states are strongly coupled by phonon exchange. We seek a self-consistent solution for the coupling between the high-lying states and the ground state pair, which occurs due to stimulated absorption and emission of phonons. In steady-state, coupling of the upper states leads to matter wave emission such that the emission of the two states is mutually coherent. The output from the transistor is thus an intensity-modulated matterwave whose frequency is approximately equal to the ground-state trap frequency.

  15. Simulation of the single event transients in a two transistor clusters CMOS 28-nm DICE cell

    International Nuclear Information System (INIS)

    Single event upsets of CMOS DICE cells depend on the cell layout. A new specific DICE cell layout design is based on two spaced transistor clusters of the DICE cell each consisting of the four transistors-one closed pair N-PMOS transistors and one opened pair N-PMOS transistors. The result of a single nuclear particle strike only on the one transistor cluster of the DICE cell is the single event transient but not the single-event upset

  16. Electrostatically Reversible Polarity of Ambipolar α-MoTe2 Transistors.

    Science.gov (United States)

    Nakaharai, Shu; Yamamoto, Mahito; Ueno, Keiji; Lin, Yen-Fu; Li, Song-Lin; Tsukagoshi, Kazuhito

    2015-06-23

    A doping-free transistor made of ambipolar α-phase molybdenum ditelluride (α-MoTe2) is proposed in which the transistor polarity (p-type and n-type) is electrostatically controlled by dual top gates. The voltage signal in one of the gates determines the transistor polarity, while the other gate modulates the drain current. We demonstrate the transistor operation experimentally, with electrostatically controlled polarity of both p- and n-type in a single transistor. PMID:25988597

  17. Sensitivity of MOS transistors to gamma and electron doses

    Energy Technology Data Exchange (ETDEWEB)

    Petr, I. (Ceske Vysoke Uceni Technicke, Prague (Czechoslovakia). Fakulta Jaderna a Fysikalne Inzenyrska); Gilar, O. (Tesla, Premysleni (Czechoslovakia). Vyzkumny Ustav Pristroju Jaderne Techniky)

    1985-03-01

    The threshold shift has been as a function of the properties of the SiO/sub 2/ layer, viz. oxide thickness and diffusion length of the charge carriers formed in the oxide layer. Experimental results obtained from gamma, fast electron, and fast neutron irradiation of MOS transistors having different oxide thickness are given. The theoretical results are compared with the measured data. The sensitivity of MOS transistors to gamma rays and fast electrons is given together with the energy dependence of radiation doses. The application of MOS transistors as dosemeters is discussed.

  18. Organic semiconductors for organic field-effect transistors

    Directory of Open Access Journals (Sweden)

    Yoshiro Yamashita

    2009-01-01

    Full Text Available The advantages of organic field-effect transistors (OFETs, such as low cost, flexibility and large-area fabrication, have recently attracted much attention due to their electronic applications. Practical transistors require high mobility, large on/off ratio, low threshold voltage and high stability. Development of new organic semiconductors is key to achieving these parameters. Recently, organic semiconductors have been synthesized showing comparable mobilities to amorphous-silicon-based FETs. These materials make OFETs more attractive and their applications have been attempted. New organic semiconductors resulting in high-performance FET devices are described here and the relationship between transistor characteristics and chemical structure is discussed.

  19. Modeling of Transistor's Tracking Behavior in Compact Models

    Directory of Open Access Journals (Sweden)

    Ning Lu

    2011-01-01

    Full Text Available We present a novel method to model the tracking behavior of semiconductor transistors undergoing across-chip variations in a compact Monte Carlo model for SPICE simulations and show an enablement of simultaneous (−1/2 tracking relations among transistors on a chip at any poly density, any gate pitch, and any physical location for the first time. At smaller separations, our modeled tracking relation versus physical location reduces to Pelgrom's characterization on device's distance-dependent mismatch. Our method is very compact, since we do not use a matrix or a set of eigen solutions to represent correlations among transistors.

  20. Toward complementary ionic circuits: the npn ion bipolar junction transistor.

    Science.gov (United States)

    Tybrandt, Klas; Gabrielsson, Erik O; Berggren, Magnus

    2011-07-01

    Many biomolecules are charged and may therefore be transported with ionic currents. As a step toward addressable ionic delivery circuits, we report on the development of a npn ion bipolar junction transistor (npn-IBJT) as an active control element of anionic currents in general, and specifically, demonstrate actively modulated delivery of the neurotransmitter glutamic acid. The functional materials of this transistor are ion exchange layers and conjugated polymers. The npn-IBJT shows stable transistor characteristics over extensive time of operation and ion current switch times below 10 s. Our results promise complementary chemical circuits similar to the electronic equivalence, which has proven invaluable in conventional electronic applications. PMID:21598973

  1. Single-photon transistor in circuit quantum electrodynamics.

    Science.gov (United States)

    Neumeier, Lukas; Leib, Martin; Hartmann, Michael J

    2013-08-01

    We introduce a circuit quantum electrodynamical setup for a "single-photon" transistor. In our approach photons propagate in two open transmission lines that are coupled via two interacting transmon qubits. The interaction is such that no photons are exchanged between the two transmission lines but a single photon in one line can completely block or enable the propagation of photons in the other line. High on-off ratios can be achieved for feasible experimental parameters. Our approach is inherently scalable as all photon pulses can have the same pulse shape and carrier frequency such that output signals of one transistor can be input signals for a consecutive transistor.

  2. GaN transistors for efficient power conversion

    CERN Document Server

    Lidow, Alex; de Rooij, Michael; Reusch, David

    2014-01-01

    The first edition of GaN Transistors for Efficient Power Conversion was self-published by EPC in 2012, and is currently the only other book to discuss GaN transistor technology and specific applications for the technology. More than 1,200 copies of the first edition have been sold through Amazon or distributed to selected university professors, students and potential customers, and a simplified Chinese translation is also available. The second edition has expanded emphasis on applications for GaN transistors and design considerations. This textbook provides technical and application-focused i

  3. Multi-gate synergic modulation in laterally coupled synaptic transistors

    Science.gov (United States)

    Zhu, Li Qiang; Xiao, Hui; Liu, Yang Hui; Wan, Chang Jin; Shi, Yi; Wan, Qing

    2015-10-01

    Laterally coupled oxide-based synaptic transistors with multiple gates are fabricated on phosphorosilicate glass electrolyte films. Electrical performance of the transistor can be evidently improved when the device is operated in a tri-gate synergic modulation mode. Excitatory post-synaptic current and paired pulse facilitation (PPF) behavior of biological synapses are mimicked, and PPF index can be effectively tuned by the voltage applied on the modulatory terminal. At last, superlinear to sublinear synaptic integration regulation is also mimicked by applying a modulatory pulse on the third modulatory terminal. The multi-gate oxide-based synaptic transistors may find potential applications in biochemical sensors and neuromorphic systems.

  4. Single bit full adder design using 8 transistors with novel 3 transistors XNOR gate

    CERN Document Server

    Kumar, Manoj; Pandey, Sujata

    2012-01-01

    In present work a new XNOR gate using three transistors has been presented, which shows power dissipation of 550.7272$\\mu$W in 0.35$\\mu$m technology with supply voltage of 3.3V. Minimum level for high output of 2.05V and maximum level for low output of 0.084V have been obtained. A single bit full adder using eight transistors has been designed using proposed XNOR cell, which shows power dissipation of 581.542$\\mu$W. Minimum level for high output of 1.97V and maximum level for low output of 0.24V is obtained for sum output signal. For carry signal maximum level for low output of 0.32V and minimum level for high output of 3.2V have been achieved. Simulations have been performed by using SPICE based on TSMC 0.35$\\mu$m CMOS technology. Power consumption of proposed XNOR gate and full adder has been compared with earlier reported circuits and proposed circuit's shows better performance in terms of power consumption and transistor count.

  5. Direct coupled amplifiers using field effect transistors

    International Nuclear Information System (INIS)

    The concept of the uni-polar field effect transistor (P.E.T.) was known before the invention of the bi-polar transistor but it is only recently that they have been made commercially. Being produced as yet only in small quantities, their price imposes a restriction on use to circuits where their peculiar properties can be exploited to the full. One such application is described here where the combination of low voltage drift and relatively low input leakage current are necessarily used together. One of the instruments used to control nuclear reactors has a logarithmic response to the mean output current from a polarised ionisation chamber. The logarithmic signal is then differentiated electrically, the result being displayed on a meter calibrated to show the reactor divergence or doubling time. If displayed in doubling time the scale is calibrated reciprocally. Because of the wide range obtained in the logarithmic section and the limited supply voltage, an output of 1 volt per decade change in ionisation current is used. Differentiating this gives a current of 1.5 x 10-8 A for p.s.D. (20 sec. doubling time) in the differentiating amplifier. To overcome some of the problems of noise due to statistical variations in input current, the circuit design necessitates a resistive path to ground at the amplifier input of 20 M.ohms. A schematic diagram is shown. 1. It is evident that a zero drift of 1% can be caused by a leakage current of 1.5 x 10-10 A or an offset voltage of 3 mV at the amplifier input. Although the presently used electrometer valve is satisfactory from the point of view of grid current, there have been sudden changes in grid to grid voltage (the valve is a double triode) of up to 10 m.V. It has been found that a pair of F.E.T's. can be used to replace the electrometer valve so long as care is taken in correct balance of the two devices. An investigation has been made into the characteristics of some fourteen devices to see whether those with very different

  6. Light-trapping and recycling for extraordinary power conversion in ultra-thin gallium-arsenide solar cells.

    Science.gov (United States)

    Eyderman, Sergey; John, Sajeev

    2016-01-01

    We demonstrate nearly 30% power conversion efficiency in ultra-thin (~200 nm) gallium arsenide photonic crystal solar cells by numerical solution of the coupled electromagnetic Maxwell and semiconductor drift-diffusion equations. Our architecture enables wave-interference-induced solar light trapping in the wavelength range from 300-865 nm, leading to absorption of almost 90% of incoming sunlight. Our optimized design for 200 nm equivalent bulk thickness of GaAs, is a square-lattice, slanted conical-pore photonic crystal (lattice constant 550 nm, pore diameter 600 nm, and pore depth 290 nm), passivated with AlGaAs, deposited on a silver back-reflector, with ITO upper contact and encapsulated with SiO2. Our model includes both radiative and non-radiative recombination of photo-generated charge carriers. When all light from radiative recombination is assumed to escape the structure, a maximum achievable photocurrent density (MAPD) of 27.6 mA/cm(2) is obtained from normally incident AM 1.5 sunlight. For a surface non-radiative recombination velocity of 10(3) cm/s, this corresponds to a solar power conversion efficiency of 28.3%. When all light from radiative recombination is trapped and reabsorbed (complete photon recycling) the power conversion efficiency increases to 29%. If the surface recombination velocity is reduced to 10 cm/sec, photon recycling is much more effective and the power conversion efficiency reaches 30.6%. PMID:27334045

  7. Light-trapping and recycling for extraordinary power conversion in ultra-thin gallium-arsenide solar cells

    Science.gov (United States)

    Eyderman, Sergey; John, Sajeev

    2016-01-01

    We demonstrate nearly 30% power conversion efficiency in ultra-thin (~200 nm) gallium arsenide photonic crystal solar cells by numerical solution of the coupled electromagnetic Maxwell and semiconductor drift-diffusion equations. Our architecture enables wave-interference-induced solar light trapping in the wavelength range from 300–865 nm, leading to absorption of almost 90% of incoming sunlight. Our optimized design for 200 nm equivalent bulk thickness of GaAs, is a square-lattice, slanted conical-pore photonic crystal (lattice constant 550 nm, pore diameter 600 nm, and pore depth 290 nm), passivated with AlGaAs, deposited on a silver back-reflector, with ITO upper contact and encapsulated with SiO2. Our model includes both radiative and non-radiative recombination of photo-generated charge carriers. When all light from radiative recombination is assumed to escape the structure, a maximum achievable photocurrent density (MAPD) of 27.6 mA/cm2 is obtained from normally incident AM 1.5 sunlight. For a surface non-radiative recombination velocity of 103 cm/s, this corresponds to a solar power conversion efficiency of 28.3%. When all light from radiative recombination is trapped and reabsorbed (complete photon recycling) the power conversion efficiency increases to 29%. If the surface recombination velocity is reduced to 10 cm/sec, photon recycling is much more effective and the power conversion efficiency reaches 30.6%. PMID:27334045

  8. Light-trapping and recycling for extraordinary power conversion in ultra-thin gallium-arsenide solar cells

    Science.gov (United States)

    Eyderman, Sergey; John, Sajeev

    2016-06-01

    We demonstrate nearly 30% power conversion efficiency in ultra-thin (~200 nm) gallium arsenide photonic crystal solar cells by numerical solution of the coupled electromagnetic Maxwell and semiconductor drift-diffusion equations. Our architecture enables wave-interference-induced solar light trapping in the wavelength range from 300-865 nm, leading to absorption of almost 90% of incoming sunlight. Our optimized design for 200 nm equivalent bulk thickness of GaAs, is a square-lattice, slanted conical-pore photonic crystal (lattice constant 550 nm, pore diameter 600 nm, and pore depth 290 nm), passivated with AlGaAs, deposited on a silver back-reflector, with ITO upper contact and encapsulated with SiO2. Our model includes both radiative and non-radiative recombination of photo-generated charge carriers. When all light from radiative recombination is assumed to escape the structure, a maximum achievable photocurrent density (MAPD) of 27.6 mA/cm2 is obtained from normally incident AM 1.5 sunlight. For a surface non-radiative recombination velocity of 103 cm/s, this corresponds to a solar power conversion efficiency of 28.3%. When all light from radiative recombination is trapped and reabsorbed (complete photon recycling) the power conversion efficiency increases to 29%. If the surface recombination velocity is reduced to 10 cm/sec, photon recycling is much more effective and the power conversion efficiency reaches 30.6%.

  9. Individual SWCNT based ionic field effect transistor

    Science.gov (United States)

    Pang, Pei; He, Jin; Park, Jae Hyun; Krstic, Predrag; Lindsay, Stuart

    2011-03-01

    Here we report that the ionic current through a single-walled carbon nanotube (SWCNT) can be effectively gated by a perpendicular electrical field from a top gate electrode, working as ionic field effect transistor. Both our experiment and simulation confirms that the electroosmotic current (EOF) is the main component in the ionic current through the SWCNT and is responsible for the gating effect. We also studied the gating efficiency as a function of solution concentration and pH and demonstrated that the device can work effectively in the physiological relevant condition. This work opens the door to use CNT based nanofluidics for ion and molecule manipulation. This work was supported by the DNA Sequencing Technology Program of the National Human Genome Research Institute (1RC2HG005625-01, 1R21HG004770-01), Arizona Technology Enterprises and the Biodesign Institute.

  10. Antiferromagnetic Spin Wave Field-Effect Transistor

    Science.gov (United States)

    Cheng, Ran; Daniels, Matthew W.; Zhu, Jian-Gang; Xiao, Di

    2016-04-01

    In a collinear antiferromagnet with easy-axis anisotropy, symmetry dictates that the spin wave modes must be doubly degenerate. Theses two modes, distinguished by their opposite polarization and available only in antiferromagnets, give rise to a novel degree of freedom to encode and process information. We show that the spin wave polarization can be manipulated by an electric field induced Dzyaloshinskii-Moriya interaction and magnetic anisotropy. We propose a prototype spin wave field-effect transistor which realizes a gate-tunable magnonic analog of the Faraday effect, and demonstrate its application in THz signal modulation. Our findings open up the exciting possibility of digital data processing utilizing antiferromagnetic spin waves and enable the direct projection of optical computing concepts onto the mesoscopic scale.

  11. Transistor Level Implementation of Digital Reversible Circuits

    Directory of Open Access Journals (Sweden)

    K.Prudhvi Raj

    2015-12-01

    Full Text Available Now a days each and every electronic gadget is desi gning smartly and provides number of applications, so these designs dissipate high amount of power. Rever sible logic is becoming one of the best emerging de sign technologies having its applications in low power C MOS, Quantum computing and Nanotechnology. Reversible logic plays an important role in the des ign of energy efficient circuits. Adders and subtra ctors are the essential blocks of the computing systems. In this paper, reversible gates and circuits are de signed and implemented in CMOS and pass transistor logic u sing Mentor graphics backend tools. A four-bit ripp le carry adder/subtractor and an eight-bit reversible Carry Skip Adder are implemented and compared with the conventional circuits

  12. Precursor Parameter Identification for Insulated Gate Bipolar Transistor (IGBT) Prognostics

    Data.gov (United States)

    National Aeronautics and Space Administration — Precursor parameters have been identified to enable development of a prognostic approach for insulated gate bipolar transistors (IGBT). The IGBT were subjected to...

  13. Microwave field-efffect transistors theory, design, and application

    CERN Document Server

    Pengelly, Raymond

    1994-01-01

    This book covers the use of devices in microwave circuits and includes such topics as semiconductor theory and transistor performance, CAD considerations, intermodulation, noise figure, signal handling, S-parameter mapping, narrow- and broadband techniques, packaging and thermal considerations.

  14. Design considerations for FET-gated power transistors

    Science.gov (United States)

    Chen, D. Y.; Chin, S. A.

    1983-01-01

    An FET-bipolar combinational power transistor configuration (tested up to 300 V, 20 A at 100 kHz) is described. The critical parameters for integrating the chips in hybrid form are examined, and an effort to optimize the overall characteristics of the configuration is discussed. Chip considerations are examined with respect to the voltage and current rating of individual chips, the FET surge capability, the choice of triple diffused transistor or epitaxial transistor for the bipolar element, the current tailing effect, and the implementation of the bipolar transistor and an FET as single chip or separate chips. Package considerations are discussed with respect to package material and geometry, surge current capability of bipolar base terminal bonding, and power losses distribution.

  15. A Field-Effect Transistor (FET) model for ASAP

    Science.gov (United States)

    Ming, L.

    1965-01-01

    The derivation of the circuitry of a field effect transistor (FET) model, the procedure for adapting the model to automated statistical analysis program (ASAP), and the results of applying ASAP on this model are described.

  16. Development and fabrication of improved power transistor switches

    Science.gov (United States)

    Hower, P. L.; Chu, C. K.

    1979-01-01

    A new class of high-voltage power transistors was achieved by adapting present interdigitated thyristor processing techniques to the fabrication of npn Si transistors. Present devices are 2.3 cm in diameter and have V sub CEO (sus) in the range of 400 to 600V. V sub CEO (sus) = 450V devices were made with an (h sub FE)(I sub C) product of 900A at V sub CE = 2.5V. The electrical performance obtained was consistent with the predictions of an optimum design theory specifically developed for power switching transistors. The device design, wafer processing, and assembly techniques are described. Experimental measurements of the dc characteristics, forward SOA, and switching times are included. A new method of characterizing the switching performance of power transistors is proposed.

  17. Bounding the total-dose response of modern bipolar transistors

    Energy Technology Data Exchange (ETDEWEB)

    Kosier, S.L.; Wei, A.; Schrimpf, R.D. [Arizona Univ., Tucson, AZ (United States). Dept. of Electrical and Computer Engineering; Combs, W.E. [Naval Surface Warfare Center-Crane, Crane, IN (United States); Fleetwood, D.M. [Sandia National Labs., Albuquerque, NM (United States); DeLaus, M. [Analog Devices, Inc., Wilmington, MA (United States); Pease, R.L. [RLP Research, Albuquerque, NM (United States)

    1994-03-01

    The base current in modern bipolar transistors saturates at large total doses once a critical oxide charge is reached. The saturated value of base current is dose-rate independent. Testing implications are discussed.

  18. A nanoscale piezoelectric transformer for low-voltage transistors.

    Science.gov (United States)

    Agarwal, Sapan; Yablonovitch, Eli

    2014-11-12

    A novel piezoelectric voltage transformer for low-voltage transistors is proposed. Placing a piezoelectric transformer on the gate of a field-effect transistor results in the piezoelectric transformer field-effect transistor that can switch at significantly lower voltages than a conventional transistor. The piezoelectric transformer operates by using one piezoelectric to squeeze another piezoelectric to generate a higher output voltage than the input voltage. Multiple piezoelectrics can be used to squeeze a single piezoelectric layer to generate an even higher voltage amplification. Coupled electrical and mechanical modeling in COMSOL predicts a 12.5× voltage amplification for a six-layer piezoelectric transformer. This would lead to more than a 150× reduction in the power needed for communications.

  19. Progresses in organic field-effect transistors and molecular electronics

    Institute of Scientific and Technical Information of China (English)

    Wu Weiping; Xu Wei; Hu Wenping; Liu Yunqi; Zhu Daoben

    2006-01-01

    In the past years,organic semiconductors have been extensively investigated as electronic materials for organic field-effect transistors (OFETs).In this review,we briefly summarize the current status of organic field-effect transistors including materials design,device physics,molecular electronics and the applications of carbon nanotubes in molecular electronics.Future prospects and investigations required to improve the OFET performance are also involved.

  20. Influence of radiation defects on power bipolar transistor structures parameters

    International Nuclear Information System (INIS)

    The changes of main dynamic and static parameters of power transistor structures under 4 MeV electron and Co60 gamma-irradiation have considered. Main radiation defects (A-centers, divacancies, other dopant-defect complexes) in n-collector layer have been determined by DLTS. The interrelationship between the dynamic transistor parameters and the dominant defect (A-center) concentration has been established

  1. Electrical properties of functionalized nanowire field effect transistors

    OpenAIRE

    Weitz, Ralf Thomas

    2008-01-01

    The utilization of functional organic materials holds great promise for applications in electronic devices. Semiconducting organic molecules are frequently used as channel material in field effect transistors, due to the ease by which they can be assembled as such components, and the ease with which their properties can be specifically tailored. An extension of the use of organic materials in field effect transistors with the potential to substantially improve the performance of such devices ...

  2. Resonant optical gating of suspended carbon nanotube transistor

    OpenAIRE

    McCoy, Robert; Anderson, Fredrick; Carter, Eric L.; Smith, Robinson L.

    2016-01-01

    Building smaller transistors with enhanced functionality is critical in extending the limits of Moores law and meeting the demands of the electronics industry. Here we demonstrate transistor operation in a suspended single carbon nanotube (CNT) using feedback-enabled radiation pressure of a near-field focused laser that enabled significant changes in conductivity of the CNT. Further, using in-situ tip-enhanced Raman spectroscopy, we show that the change in conductivity of over five orders in ...

  3. COULOMB BLOCKADE OSCILLATIONS OF Si SINGLE-ELECTRON TRANSISTORS

    Institute of Scientific and Technical Information of China (English)

    王太宏; 李宏伟; 周均铭

    2001-01-01

    Coulomb blockade oscillations of Si single-electron transistors, which are fabricated completely by the conventional photolithography technique, have been investigated. Most of the single-electron transistors clearly show Coulomb blockade oscillations and these oscillations can be periodic by applying negative voltages to the in-plane gates. A shift of the peak positions is observed at high temperatures. It is also found that the fluctuation of the peak spacing cannot be neglected.

  4. Single electron transistors with high quality superconducting niobium islands

    OpenAIRE

    Dolata, R.; Scherer, H.; Zorin, A. B.; J. Niemeyer

    2001-01-01

    Deep submicron Al-AlOx-Nb tunnel junctions and single electron transistors with niobium islands were fabricated by electron beam gun shadow evaporation. Using stencil masks consisting of the thermostable polymer polyethersulfone (PES) and germanium, high quality niobium patterns with good superconducting properties and a gap energy of up to 2Delta = 2.5 meV for the niobium were achieved. The I(U) characteristics of the transistors show special features due to tunneling of single Cooper pairs ...

  5. Wet Organic Field Effect Transistor as DNA sensor

    OpenAIRE

    Chiu, Yu-Jui

    2008-01-01

    Label-free detection of DNA has been successfully demonstrated on field effect transistor (FET) based devices. Since conducting organic materials was discovered and have attracted more and more research efforts by their profound advantages, this work will focus on utilizing an organic field effect transistor (OFET) as DNA sensor. An OFET constructed with a transporting fluidic channel, WetOFET, forms a fluid-polymer (active layer) interface where the probe DNA can be introduced. DNA hybridiza...

  6. Sidewall penetration of dislocations in ion-implanted bipolar transistors

    International Nuclear Information System (INIS)

    Phosphorus-doped emitters have been formed by either conventional diffusion or implantation, anneal, and drive-in processes. Transmission electron microscopy and measurements of transistor characteristics were made to evaluate the two processes. Comparison of structures with similar dislocation densities indicated that the dislocations in the implanted structures penetrated the emitter-base sidewall, whereas the dislocations in the diffused structure were confined to the emitter region. The transistor with extended dislocations exhibited high leakage current and excess popcorn noise generating

  7. Reconfigurable quadruple quantum dots in a silicon nanowire transistor

    OpenAIRE

    Betz, A. C.; Tagliaferri, M. L. V.; Vinet, M.; Broström, M.; Sanquer, M.; Ferguson, A.J.; Gonzalez-Zalba, M. F.

    2016-01-01

    We present a novel reconfigurable metal-oxide-semiconductor multi-gate transistor that can host a quadruple quantum dot in silicon. The device consist of an industrial quadruple-gate silicon nanowire field-effect transistor. Exploiting the corner effect, we study the versatility of the structure in the single quantum dot and the serial double quantum dot regimes and extract the relevant capacitance parameters. We address the fabrication variability of the quadruple-gate approach which, paired...

  8. Thermal Runaway Robustness of SiC VJFETs

    OpenAIRE

    Ouaida, Rémy; Buttay, Cyril; Hoang, Anh Dung; Riva, Raphaël; Bergogne, Dominique; Morel, Hervé; Raynaud, Christophe; Morel, Florent

    2013-01-01

    Silicon Carbide (SiC) Junction-Field Effect Transistors (JFETs) are attractive devices for power electronics. Their high temperature capability should allow them to operate with a reduced cooling system. However, experiments described in this paper conclude to the existence of runaway conditions in which these transistors will reach destructive temperatures.

  9. Large scale electromechanical transistor with application in mass sensing

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Leisheng; Li, Lijie, E-mail: L.Li@swansea.ac.uk [Multidisciplinary Nanotechnology Centre, College of Engineering, Swansea University, Swansea SA2 8PP (United Kingdom)

    2014-12-07

    Nanomechanical transistor (NMT) has evolved from the single electron transistor, a device that operates by shuttling electrons with a self-excited central conductor. The unfavoured aspects of the NMT are the complexity of the fabrication process and its signal processing unit, which could potentially be overcome by designing much larger devices. This paper reports a new design of large scale electromechanical transistor (LSEMT), still taking advantage of the principle of shuttling electrons. However, because of the large size, nonlinear electrostatic forces induced by the transistor itself are not sufficient to drive the mechanical member into vibration—an external force has to be used. In this paper, a LSEMT device is modelled, and its new application in mass sensing is postulated using two coupled mechanical cantilevers, with one of them being embedded in the transistor. The sensor is capable of detecting added mass using the eigenstate shifts method by reading the change of electrical current from the transistor, which has much higher sensitivity than conventional eigenfrequency shift approach used in classical cantilever based mass sensors. Numerical simulations are conducted to investigate the performance of the mass sensor.

  10. Large scale electromechanical transistor with application in mass sensing

    International Nuclear Information System (INIS)

    Nanomechanical transistor (NMT) has evolved from the single electron transistor, a device that operates by shuttling electrons with a self-excited central conductor. The unfavoured aspects of the NMT are the complexity of the fabrication process and its signal processing unit, which could potentially be overcome by designing much larger devices. This paper reports a new design of large scale electromechanical transistor (LSEMT), still taking advantage of the principle of shuttling electrons. However, because of the large size, nonlinear electrostatic forces induced by the transistor itself are not sufficient to drive the mechanical member into vibration—an external force has to be used. In this paper, a LSEMT device is modelled, and its new application in mass sensing is postulated using two coupled mechanical cantilevers, with one of them being embedded in the transistor. The sensor is capable of detecting added mass using the eigenstate shifts method by reading the change of electrical current from the transistor, which has much higher sensitivity than conventional eigenfrequency shift approach used in classical cantilever based mass sensors. Numerical simulations are conducted to investigate the performance of the mass sensor

  11. A final report for: Gallium arsenide P-I-N detectors for high-sensitivity imaging of thermal neutrons

    International Nuclear Information System (INIS)

    This SBIR Phase I developed neutron detectors made FR-om gallium arsenide (GaAs) p-type/ intrinsic/n-type (P-I-N) diodes grown by metalorganic chemical vapor deposition (MOCVD) onto semi-insulating (S1) bulk GaAs wafers. A layer of isotonically enriched boron-10 evaporated onto the FR-ont surface serves to convert incoming neutrons into lithium ions and a 1.47 MeV alpha particle which creates electron-hole pairs that are detected by the GaAs diode. Various thicknesses of ''intrinsic'' (I) undoped GaAs were tested, as was use of a back-surface field (BSF) formed FR-om a layer of AlxGa1-xAs. Schottky-barrier diodes formed FR-om the same structures without the p+ GaAs top layer were tested as a comparison. After mesa etching and application of contacts, devices were tested in visible light before application of the boron coating. Internal quantum efficiency (IQE) of the best diode near the GaAs bandedge is over 90%. The lowest dark current measured is 1 x 10-12 amps at -1 V on a 3mm x 3mm diode, or a density of 1.1 x 10-11 amps cm-2, with many of the diode structures tested having nearly similar results. The PIN diodes were significantly better than the Schottky barrier device, which had six orders of magnitude higher dark current. Diodes were characterized in terms of their current-mode response to 5.5 MeV alpha particles FR-om 241-Americium. These radiation-induced currents were as high as 9.78 x 10-7 A cm-1 on a PIN device with an AlxGa1-xAs BSF. Simple PIN diodes had currents as high as 2.44 x 10-7 A cm-2, with thicker undoped layers showing better sensitivity. Boron coatings were applied, and response to neutrons tested at University of Michigan by Dr. Doug McGregor. Devices with PIN and Schottky barrier designs showed neutron detection efficiencies as high as 2% on 5 (micro)m thick devices, with no need for external bias voltages. PIN diodes showed higher breakdown voltages and lower noise characteristics than did the Schottky barrier design. Uniformity of

  12. Fast Flexible Transistors with a Nanotrench Structure

    Science.gov (United States)

    Seo, Jung-Hun; Ling, Tao; Gong, Shaoqin; Zhou, Weidong; Ma, Alice L.; Guo, L. Jay; Ma, Zhenqiang

    2016-04-01

    The simplification of fabrication processes that can define very fine patterns for large-area flexible radio-frequency (RF) applications is very desirable because it is generally very challenging to realize submicron scale patterns on flexible substrates. Conventional nanoscale patterning methods, such as e-beam lithography, cannot be easily applied to such applications. On the other hand, recent advances in nanoimprinting lithography (NIL) may enable the fabrication of large-area nanoelectronics, especially flexible RF electronics with finely defined patterns, thereby significantly broadening RF applications. Here we report a generic strategy for fabricating high-performance flexible Si nanomembrane (NM)-based RF thin-film transistors (TFTs), capable of over 100 GHz operation in theory, with NIL patterned deep-submicron-scale channel lengths. A unique 3-dimensional etched-trench-channel configuration was used to allow for TFT fabrication compatible with flexible substrates. Optimal device parameters were obtained through device simulation to understand the underlying device physics and to enhance device controllability. Experimentally, a record-breaking 38 GHz maximum oscillation frequency fmax value has been successfully demonstrated from TFTs with a 2 μm gate length built with flexible Si NM on plastic substrates.

  13. Fast Flexible Transistors with a Nanotrench Structure.

    Science.gov (United States)

    Seo, Jung-Hun; Ling, Tao; Gong, Shaoqin; Zhou, Weidong; Ma, Alice L; Guo, L Jay; Ma, Zhenqiang

    2016-04-20

    The simplification of fabrication processes that can define very fine patterns for large-area flexible radio-frequency (RF) applications is very desirable because it is generally very challenging to realize submicron scale patterns on flexible substrates. Conventional nanoscale patterning methods, such as e-beam lithography, cannot be easily applied to such applications. On the other hand, recent advances in nanoimprinting lithography (NIL) may enable the fabrication of large-area nanoelectronics, especially flexible RF electronics with finely defined patterns, thereby significantly broadening RF applications. Here we report a generic strategy for fabricating high-performance flexible Si nanomembrane (NM)-based RF thin-film transistors (TFTs), capable of over 100 GHz operation in theory, with NIL patterned deep-submicron-scale channel lengths. A unique 3-dimensional etched-trench-channel configuration was used to allow for TFT fabrication compatible with flexible substrates. Optimal device parameters were obtained through device simulation to understand the underlying device physics and to enhance device controllability. Experimentally, a record-breaking 38 GHz maximum oscillation frequency fmax value has been successfully demonstrated from TFTs with a 2 μm gate length built with flexible Si NM on plastic substrates.

  14. A Vertically Integrated Junctionless Nanowire Transistor.

    Science.gov (United States)

    Lee, Byung-Hyun; Hur, Jae; Kang, Min-Ho; Bang, Tewook; Ahn, Dae-Chul; Lee, Dongil; Kim, Kwang-Hee; Choi, Yang-Kyu

    2016-03-01

    A vertically integrated junctionless field-effect transistor (VJ-FET), which is composed of vertically stacked multiple silicon nanowires (SiNWs) with a gate-all-around (GAA) structure, is demonstrated on a bulk silicon wafer for the first time. The proposed VJ-FET mitigates the issues of variability and fabrication complexity that are encountered in the vertically integrated multi-NW FET (VM-FET) based on an identical structure in which the VM-FET, as recently reported, harnesses a source and drain (S/D) junction for its operation and is thus based on the inversion mode. Variability is alleviated by bulk conduction in a junctionless FET (JL-FET), where current flows through the core of the SiNW, whereas it is not mitigated by surface conduction in an inversion mode FET (IM-FET), where current flows via the surface of the SiNW. The fabrication complexity is reduced by the inherent JL structure of the JL-FET because S/D formation is not required. In contrast, it is very difficult to dope the S/D when it is positioned at each floor of a tall SiNW with greater uniformity and with less damage to the crystalline structure of the SiNW in a VM-FET. Moreover, when the proposed VJ-FET is used as nonvolatile flash memory, the endurance and retention characteristics are improved due to the above-mentioned bulk conduction. PMID:26885948

  15. Fast Flexible Transistors with a Nanotrench Structure.

    Science.gov (United States)

    Seo, Jung-Hun; Ling, Tao; Gong, Shaoqin; Zhou, Weidong; Ma, Alice L; Guo, L Jay; Ma, Zhenqiang

    2016-01-01

    The simplification of fabrication processes that can define very fine patterns for large-area flexible radio-frequency (RF) applications is very desirable because it is generally very challenging to realize submicron scale patterns on flexible substrates. Conventional nanoscale patterning methods, such as e-beam lithography, cannot be easily applied to such applications. On the other hand, recent advances in nanoimprinting lithography (NIL) may enable the fabrication of large-area nanoelectronics, especially flexible RF electronics with finely defined patterns, thereby significantly broadening RF applications. Here we report a generic strategy for fabricating high-performance flexible Si nanomembrane (NM)-based RF thin-film transistors (TFTs), capable of over 100 GHz operation in theory, with NIL patterned deep-submicron-scale channel lengths. A unique 3-dimensional etched-trench-channel configuration was used to allow for TFT fabrication compatible with flexible substrates. Optimal device parameters were obtained through device simulation to understand the underlying device physics and to enhance device controllability. Experimentally, a record-breaking 38 GHz maximum oscillation frequency fmax value has been successfully demonstrated from TFTs with a 2 μm gate length built with flexible Si NM on plastic substrates. PMID:27094686

  16. Scaling properties of ballistic nano-transistors

    Directory of Open Access Journals (Sweden)

    Wulf Ulrich

    2011-01-01

    Full Text Available Abstract Recently, we have suggested a scale-invariant model for a nano-transistor. In agreement with experiments a close-to-linear thresh-old trace was found in the calculated I D - V D-traces separating the regimes of classically allowed transport and tunneling transport. In this conference contribution, the relevant physical quantities in our model and its range of applicability are discussed in more detail. Extending the temperature range of our studies it is shown that a close-to-linear thresh-old trace results at room temperatures as well. In qualitative agreement with the experiments the I D - V G-traces for small drain voltages show thermally activated transport below the threshold gate voltage. In contrast, at large drain voltages the gate-voltage dependence is weaker. As can be expected in our relatively simple model, the theoretical drain current is larger than the experimental one by a little less than a decade.

  17. Electron irradiation effects on power MOS transistors

    Energy Technology Data Exchange (ETDEWEB)

    Frisina, F.; Tavolo, N. (S.G.S. Thomson Microelectronics, Catania (Italy)); Gombia, E.; Mosca, R. (Consiglio Nazionale delle Ricerche, Parma (Italy). Ist. MASPEC); Chirco, P.; Fuochi, P.G. (Consiglio Nazionale delle Ricerche, Bologna (Italy). Lab. di Fotochimica e Radiazioni d' Alta Energia)

    1990-01-01

    Electron irradiation has been used to enhance the switching speed of the internal diode in high-voltage power MOS structures (BV{sub DSS} > 500 V). By using 12 MeV electron irradiation at room temperature it has been found that the reverse recovery time and the reverse recovery charge of power MOS internal diode can be reduced in a well controlled manner up to 70% and 90% of their initial value respectively increasing the radiation dose from 0 to 15 Mrads. Anyway an undesirable decrease of about 3V has been observed in the gate threshold voltage. This effect has been ascribed to the damage produced in the gate oxide of the device due to the electron irradiation. By annealing the device at temperature >315{sup 0}C it has been possible to restore the threshold voltage without heavily enhancing the carrier lifetime. DLTS measurements have been performed on electron-irradiated devices to identify the recombination centres introduced in the forbidden gap of the silicon. A comparison has been made with gold-diffused devices. The results obtained confirm that electron irradiation is feasible for power MOS transistors. (author).

  18. Advanced insulated gate bipolar transistor gate drive

    Science.gov (United States)

    Short, James Evans; West, Shawn Michael; Fabean, Robert J.

    2009-08-04

    A gate drive for an insulated gate bipolar transistor (IGBT) includes a control and protection module coupled to a collector terminal of the IGBT, an optical communications module coupled to the control and protection module, a power supply module coupled to the control and protection module and an output power stage module with inputs coupled to the power supply module and the control and protection module, and outputs coupled to a gate terminal and an emitter terminal of the IGBT. The optical communications module is configured to send control signals to the control and protection module. The power supply module is configured to distribute inputted power to the control and protection module. The control and protection module outputs on/off, soft turn-off and/or soft turn-on signals to the output power stage module, which, in turn, supplies a current based on the signal(s) from the control and protection module for charging or discharging an input capacitance of the IGBT.

  19. Variable Temperature High-Frequency Response of Heterostructure Transistors

    Science.gov (United States)

    Laskar, Joy

    1992-01-01

    The development of high performance heterostructure transistors is essential for emerging opto-electronic integrated circuits (OEICs) and monolithic microwave integrated circuits (MMICs). Applications for OEICs and MMICs include the rapidly growing telecommunications and personal communications markets. The key to successful OEIC and MMIC chip sets is the development of high performance, cost-effective technologies. In this work, several different transistor structures are investigated to determine the potential for high speed performance and the physical mechanisms controlling the ultimate device operation. A cryogenic vacuum microwave measurement system has been developed to study the high speed operation of modulation doped field-effect transistors (MODFETs), doped channel metal insulator field-effect transistors (MISFETs), and metal semiconductor field-effect transistors (MESFETs). This study has concluded that the high field velocity and not the low field mobility is what controls high frequency operation of GaAs based field-effect transistors. Both Al_{rm x} Ga_{rm 1-x}As/GaAs and InP/In_{rm y}Ga _{rm 1-y}As heterostructure bipolar transistors (HBTs) have also been studied at reduced lattice temperatures to understand the role of diffusive transport in the Al_{rm x} Ga_{rm 1-x}As/GaAs HBT and nonequilibrium transport in the InP/In _{rm y}Ga_ {rm 1-y}As HBT. It is shown that drift/diffusion formulation must be modified to accurately estimate the base delay time in the conventional Al _{rm x}Ga_ {rm 1-x}As/GaAs HBT. The reduced lattice temperature operation of the InP/In_ {rm y}Ga_{rm 1-y}As HBT demonstrates extreme nonequilibrium transport in the neutral base and collector space charge region with current gain cut-off frequency exceeding 300 GHz, which is the fastest reported transistor to date. Finally, the MODFET has been investigated as a three-terminal negative differential resistance (NDR) transistor. The existence of real space transfer is confirmed by

  20. Transistor reset preamplifier for high-rate high-resolution spectroscopy

    International Nuclear Information System (INIS)

    Pulsed transistor reset of high resolution charge sensitive preamplifiers used in cooled semiconductor spectrometers can sometimes have an advantage over pulsed light reset systems. Several versions of transistor reset spectrometers using both silicon and germanium detectors have been built. This paper discusses the advantages of the transistor reset system and illustrates several configurations of the packages used for the FET and reset transistor. It also describes the preamplifer circuit and shows the performance of the spectrometer at high rates

  1. Characterisation of silicon carbide schottky diodes and coolmos transistors at high temperature

    OpenAIRE

    Khatir, Z.; L. Dupont; Lefebvre, S.; Bontemps, S.; MEURET,R

    2004-01-01

    The highly doping level of the base region of coolmos transistors allows higher temperature operations than with conventional silicon transistors having the same blocking voltage. In this paper, the temperature influence on different sic schottky diodes and silicon coolmos transistors characteritics is discussed. Comparisons are made and the results on the behaviour of sic schottky diodes and coolmos transistors in the on-state and in switching operations.

  2. Transistor needle chip for recording in brain tissue

    Science.gov (United States)

    Felderer, Florian; Fromherz, Peter

    2011-07-01

    We report on a proof-of-principle experiment for the direct interfacing of transistors with intact brain tissue. A transistor needle chip (TNC) with a TiO2 surface is fabricated from a silicon-on-insulator wafer and impaled into an acute brain slice cut from hippocampus of the rat. While stimulating the Schaffer collateral, a local field potential is recorded in stratum radiatum of the CA1 region with field-effect transistors in the central part of the slice where the tissue is not damaged by the cutting process. After the impalement, the signal amplitude is small. Within an hour, it increases to a stable level around -2 mV as is recorded with a conventional micropipette electrode. The recovery indicates that the tissue is able to adapt to the impaled chip. Upon repeated impalements at the same position, the large signal is observed without delay. A profile of the transistor signal across the slice is due to the boundary conditions of a brain slice with both surfaces held near ground potential. The experiments with the TNC prototype are a basis for the development of silicon needle chips with a large multi-transistor array (MTA) for applications in brain-computer interfacing.

  3. Use of NPN bipolar transistors for silicon equivalent neutron damage

    International Nuclear Information System (INIS)

    With the closing of the Northrop Triga Reactor, Northrop shifted its neutron irradiations to the several government Fast Burst Reactors. As a control, an inexpensive NPN bipolar transistor was chosen to monitor the silicon equivalent damage created by the differing neutron spectra. Noticeable biases occurred between the comparisons with 1 Mev silicon equivalent dosimetry reported by the several facilities and the damage observed in the monitor transistors and other semiconductors being irradiated. A special effort was committed to automate the measurement of the monitor transistors. Their behavior was then studied and quantified so that a more precise determination of the neutron fluence could be obtained. The techniques needed for accurate read-out of fluences from monitor transistors, with supporting data, is presented. The variabilities are mostly related to the choice of monitor transistor, test conditions, ambient and self-heating, and timing/annealing of the measurements. The occurrence of reverse annealing, varying with measurement current, is detailed. Also the monitoring of VBE as a thermometer to correct the damage factor to a standard temperature is noted. The electrical measurement errors have been made negligible. Some preliminary comparisons are given for the several facilities, using their historic 1 Mev (Si) sulfur/conversions. These comparisons do not include any adjustments for the biases developed by experiment positioning or recent changes in the silicon 1 Mev damage equivalence curve

  4. Exfoliated multilayer MoTe2 field-effect transistors

    Science.gov (United States)

    Fathipour, S.; Ma, N.; Hwang, W. S.; Protasenko, V.; Vishwanath, S.; Xing, H. G.; Xu, H.; Jena, D.; Appenzeller, J.; Seabaugh, A.

    2014-11-01

    The properties of multilayer exfoliated MoTe2 field-effect transistors (FETs) on SiO2 were investigated for channel thicknesses from 6 to 44 monolayers (MLs). All transistors showed p-type conductivity at zero back-gate bias. For channel thicknesses of 8 ML or less, the transistors exhibited ambipolar characteristics. ON/OFF current ratio was greatest, 1 × 105, for the transistor with the thinnest channel, 6 ML. Devices showed a clear photoresponse to wavelengths between 510 and 1080 nm at room temperature. Temperature-dependent current-voltage measurements were performed on a FET with 30 layers of MoTe2. When the channel is turned-on and p-type, the temperature dependence is barrier-limited by the Au/Ti/MoTe2 contact with a hole activation energy of 0.13 eV. A long channel transistor model with Schottky barrier contacts is shown to be consistent with the common-source characteristics.

  5. Subthreshold Leakage Minimization in MOSFET using Sleep Transistor Circuit

    Directory of Open Access Journals (Sweden)

    Shailesh Kumar Mukati

    2014-05-01

    Full Text Available The excessive power consumption has become one in all the first hindrances to the more advances of CMOS integrated circuits. Low power circuit style is a crucial analysis space. there are 3 primary stimuli for low power circuit design: setting friendly inexperienced computing, battery life extension for mobile applications, and rising self-sufficing battery replacement free applications like intelligent sensing element nodes. The leakage current in MOSFET is due to subthreshold leakage current due to parasitic pn junctions. The sleep transistor is use between CMOS logic and supply rail. Our technique, sleep transistor square measure placed between the circuits offer and provide rails to show off the run current flow throughout idle time this will be done by victimization one PMOS transistor and one NMOS transistor nonparallel with the transistors of every logic block to make a virtual ground and a virtual power supply. constant estimation victimization town simulation will acquire a comparatively correct estimation of the run distribution; but, this methodology needs an extended simulation time and is therefore computationally expensive

  6. Ternary arsenides based on platinum–indium and palladium–indium fragments of the Cu{sub 3}Au-type: Crystal structures and chemical bonding

    Energy Technology Data Exchange (ETDEWEB)

    Zakharova, Elena Yu.; Andreeva, Natalia A.; Kazakov, Sergey M. [Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, GSP-1, 119991 Moscow (Russian Federation); Kuznetsov, Alexey N., E-mail: alexei@inorg.chem.msu.ru [Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, GSP-1, 119991 Moscow (Russian Federation); N.S. Kurnakov Institute of General and Inorganic Chemistry of Russian Academy of Sciences, Leninskii pr. 31, 119991 Moscow (Russian Federation)

    2015-02-05

    Highlights: • Three metal-rich platinum–indium and palladium–indium arsenides were synthesized. • Their crystal structures were determined from powder XRD. • Electronic structures and bonding were studied using DFT/FP-LAPW calculations. • Multi-centered Pt–In or Pd–In bonding was revealed using ELF and ELI-D analysis. • Extra pairwise Pt–Pt interactions are observed only for Pt-based compounds. - Abstract: Three metal-rich palladium–indium and platinum–indium arsenides, Pd{sub 5}InAs, Pt{sub 5}InAs, and Pt{sub 8}In{sub 2}As, were synthesized using a high-temperature ampoule technique. Their crystal structures were determined from Rietveld analysis of powder diffraction data. All the compounds crystallize in tetragonal system with P4/mmm space group (Pd{sub 5}InAs: a = 3.9874(1) Å, c = 6.9848(2) Å, Z = 1, R{sub p} = 0.053; R{sub b} = 0.013; Pt{sub 5}InAs: a = 3.9981(2) Å, c = 7.0597(4) Å, Z = 1, R{sub p} = 0.058, R{sub b} = 0.016; Pt{sub 8}In{sub 2}As: a = 3.9872(3) Å, c = 11.1129(7) Å, Z = 1, R{sub p} = 0.047; R{sub b} = 0.014). The first two compounds belong to the Pd{sub 5}TlAs structure type, while the third one is isotypic with the recently discovered Pd{sub 8}In{sub 2}Se. Main structural units in all arsenides are indium-centered [TM{sub 12}In] cuboctahedra (TM = Pd, Pt) of the Cu{sub 3}Au type, single- and double-stacked along the c axis in TM{sub 5}InAs and Pt{sub 8}In{sub 2}As, respectively, alternating with [TM{sub 8}As] rectangular prisms. DFT electronic structure calculations predict all three compounds to be 3D metallic conductors and Pauli-like paramagnets. According to the bonding analysis based on the electron localization function and electron localizability indicator topologies, all compounds feature multi-centered interactions between transition metal and indium in their heterometallic fragments. Additionally, pairwise interactions between platinum atoms are also observed, indicating a somewhat more localized bonding

  7. Theoretical values of various parameters in the Gummel-Poon model of a bipolar junction transistor

    Science.gov (United States)

    Benumof, R.; Zoutendyk, J.

    1986-01-01

    Various parameters in the Gummel-Poon model of a bipolar junction transistor are expressed in terms of the basic structure of a transistor. A consistent theoretical approach is used which facilitates an understanding of the foundations and limitations of the derived formulas. The results enable one to predict how changes in the geometry and composition of a transistor would affect performance.

  8. Ambipolar Organic Tri-Gate Transistor for Low-Power Complementary Electronics

    NARCIS (Netherlands)

    Torricelli, F.; Ghittorelli, M.; Smits, E.C.P.; Roelofs, C.W.S.; Janssen, R.A.J.; Gelinck, G.H.; Kovács-Vajna, Z.M.; Cantatore, E.

    2016-01-01

    Ambipolar transistors typically suffer from large off-current inherently due to ambipolar conduction. Using a tri-gate transistor it is shown that it is possible to electrostatically switch ambipolar polymer transistors from ambipolar to unipolar mode. In unipolar mode, symmetric characteristics wit

  9. Development and Experimental Evaluation of an Automated Multi-Media Course on Transistors.

    Science.gov (United States)

    Whitted, J.H., Jr.; And Others

    A completely automated multi-media self-study program for teaching a portion of electronic solid-state fundamentals was developed. The subject matter areas included were fundamental theory of transistors, transistor amplifier fundamentals, and simple mathematical analysis of transistors including equivalent circuits, parameters, and characteristic…

  10. Investigation of Impact of the Gate Circuitry on IGBT Transistor Dynamic Parameters

    Directory of Open Access Journals (Sweden)

    Vytautas Bleizgys

    2011-03-01

    Full Text Available The impact of Insulated Gate Bipolar Transistor driver circuit parameters on the rise and fall time of the collector current and voltage collector-emitter was investigated. The influence of transistor driver circuit parameters on heating of Insulated Gate Bipolar Transistors was investigated as well.Article in Lithuanian

  11. Single-ZnO-Nanobelt-Based Single-Electron Transistors

    Science.gov (United States)

    Ji, Xiao-Fan; Xu, Zheng; Cao, Shuo; Qiu, Kang-Sheng; Tang, Jing; Zhang, Xi-Tian; Xu, Xiu-Lai

    2014-06-01

    We fabricate single electron transistors based on a single ZnO nanobelt using standard micro-fabrication techniques. The transport properties of the devices are characterized at room temperature and at low temperature (4.2 K). At room temperature, the source-drain current increases linearly as the bias voltage increases, indicating a good ohmic contact in the transistors. At 4.2 K, a Coulomb blockade regime is observed up to a bias voltage of a few millivolts. With scanning the back gate voltage, Coulomb oscillations can be clearly resolved with a period around 1 V. From the oscillations, the charging energy for the single electron transistor is calculated to be about 10 meV, which suggests that confined quantum dots exist with sizes around 35 nm in diameter. The irregular Coulomb diamonds are observed due to the multi-tunneling junctions between dots in the nanobelt.

  12. Physics-based stability analysis of MOS transistors

    Science.gov (United States)

    Ferrara, A.; Steeneken, P. G.; Boksteen, B. K.; Heringa, A.; Scholten, A. J.; Schmitz, J.; Hueting, R. J. E.

    2015-11-01

    In this work, a physics-based model is derived based on a linearization procedure for investigating the electrical, thermal and electro-thermal instability of power metal-oxide-semiconductor (MOS) transistors. The proposed model can be easily interfaced with a circuit or device simulator to perform a failure analysis, making it particularly useful for power transistors. Furthermore, it allows mapping the failure points on a three-dimensional (3D) space defined by the gate-width normalized drain current, drain voltage and junction temperature. This leads to the definition of the Safe Operating Volume (SOV), a powerful frame work for making failure predictions and determining the main root of instability (electrical, thermal or electro-thermal) in different bias and operating conditions. A comparison between the modeled and the measured SOV of silicon-on-insulator (SOI) LDMOS transistors is reported to support the validity of the proposed stability analysis.

  13. Electronic transport characteristics in silicon nanotube field-effect transistors

    Science.gov (United States)

    Shan, Guangcun; Wang, Yu; Huang, Wei

    2011-07-01

    The successful synthesis of silicon nanotubes (SiNTs) has been reported, making these nanostructures a new novel candidate for future nanodevices. By self-consistently solving the Poisson equations using the non-equilibrium Green's function (NEGF) formalism, we investigate the electronic transport and the role of gate bias in affecting the drive current of single-walled silicon nanotube (SW-SiNT) field-effect transistors (FETs). By comparison of a SW-CNT FET, it is found that the SW-SiNT with a high- k HfO gate oxide is a promising candidate for nanotube transistor with better performance. The results discussed here would serve as a versatile and powerful guideline for future experimental studies of SW-SiNT-based transistor with the purpose of exploring device application for nanoelectronics.

  14. Calculating drain delay in high electron mobility transistors

    Science.gov (United States)

    Coffie, R.

    2015-12-01

    An expression for the signal delay (drain delay) associated with electrons traveling through the gate-drain depletion region has been obtained for nonuniform electron velocity. Due to the presence of the gate metal, the signal delay through the gate-drain depletion region was shown to be larger than the signal delay in the base-collector depletion region of a bipolar transistor when equal depletion lengths and velocity profiles were assumed. Drain delay is also shown to be larger in transistors with field plates (independent of field plate connection) compared to transistors without field plates when equal depletion lengths and velocity profiles were assumed. For the case of constant velocity, two expressions for the proportionality constant relating drain delay and electron transit time across the depletion were obtained.

  15. Nanowire transistors physics of devices and materials in one dimension

    CERN Document Server

    Colinge, Jean-Pierre

    2016-01-01

    From quantum mechanical concepts to practical circuit applications, this book presents a self-contained and up-to-date account of the physics and technology of nanowire semiconductor devices. It includes a unified account of the critical ideas central to low-dimensional physics and transistor physics which equips readers with a common framework and language to accelerate scientific and technological developments across the two fields. Detailed descriptions of novel quantum mechanical effects such as quantum current oscillations, the metal-to-semiconductor transition and the transition from classical transistor to single-electron transistor operation are described in detail, in addition to real-world applications in the fields of nanoelectronics, biomedical sensing techniques, and advanced semiconductor research. Including numerous illustrations to help readers understand these phenomena, this is an essential resource for researchers and professional engineers working on semiconductor devices and materials in ...

  16. Single-Photon Transistor Using a Förster Resonance

    Science.gov (United States)

    Tiarks, Daniel; Baur, Simon; Schneider, Katharina; Duerr, Stephan; Rempe, Gerhard

    2015-05-01

    An all-optical transistor is a device in which a gate light pulse switches the transmission of a target light pulse with a gain above unity. The gain quantifies the change of the transmitted target photon number per incoming gate photon. We study the quantum limit of one incoming gate photon and observe a gain of 20. The gate pulse is stored as a Rydberg excitation in an ultracold gas. The transmission of the subsequent target pulse is suppressed by Rydberg blockade which is enhanced by a Förster resonance. The detected target photons reveal in a single shot with a fidelity above 0.86 whether a Rydberg excitation was created during the gate pulse. The gain offers the possibility to distribute the transistor output to the inputs of many transistors, thus making complex computational tasks possible.

  17. Swift Heavy Ion Irradiation Effects on NPN rf Power Transistors

    Science.gov (United States)

    Pushpa, N.; Prakash, A. P. Gnana; Gupta, S. K.; Revannasiddaiah, D.

    2011-07-01

    The dc characteristics of NPN rf power transistors were studied systematically before and after irradiation by 50 MeV Li3+ ions, 100 MeV F8+ ions and 140 MeV Si10+ ions in the dose range of 100 krad to 100 Mrad. The transistor parameters such as excess base current (ΔIB = IBpost-IBpre), dc current gain (hFE), and collector-saturation current (ICSat) were determined before and after irradiation. The base current (IB) was found to increase significantly after ion irradiation and this in turn decreases the hFE of the transistors. Further, the output characteristics of the irradiated devices exhibit the decrease in the collector current at the saturation region (ICSat) with increase of ion dose.

  18. Vertically aligned carbon nanotube field-effect transistors

    KAUST Repository

    Li, Jingqi

    2012-10-01

    Vertically aligned carbon nanotube field-effect transistors (CNTFETs) have been developed using pure semiconducting carbon nanotubes. The source and drain were vertically stacked, separated by a dielectric, and the carbon nanotubes were placed on the sidewall of the stack to bridge the source and drain. Both the effective gate dielectric and gate electrode were normal to the substrate surface. The channel length is determined by the dielectric thickness between source and drain electrodes, making it easier to fabricate sub-micrometer transistors without using time-consuming electron beam lithography. The transistor area is much smaller than the planar CNTFET due to the vertical arrangement of source and drain and the reduced channel area. © 2012 Elsevier Ltd. All rights reserved.

  19. Integrated logic circuits using single-atom transistors.

    Science.gov (United States)

    Mol, J A; Verduijn, J; Levine, R D; Remacle, F; Rogge, S

    2011-08-23

    Scaling down the size of computing circuits is about to reach the limitations imposed by the discrete atomic structure of matter. Reducing the power requirements and thereby dissipation of integrated circuits is also essential. New paradigms are needed to sustain the rate of progress that society has become used to. Single-atom transistors, SATs, cascaded in a circuit are proposed as a promising route that is compatible with existing technology. We demonstrate the use of quantum degrees of freedom to perform logic operations in a complementary-metal-oxide-semiconductor device. Each SAT performs multilevel logic by electrically addressing the electronic states of a dopant atom. A single electron transistor decodes the physical multivalued output into the conventional binary output. A robust scalable circuit of two concatenated full adders is reported, where by utilizing charge and quantum degrees of freedom, the functionality of the transistor is pushed far beyond that of a simple switch. PMID:21808050

  20. A single photoelectron transistor for quantum optical communications

    CERN Document Server

    Kosaka, H; Robinson, H D; Bandaru, P; Makita, K; Yablonovitch, E B; Kosaka, Hideo; Rao, Deepak S.; Robinson, Hans D.; Bandaru, Prabhakar; Makita, Kikuo; Yablonovitch, Eli

    2003-01-01

    A single photoelectron can be trapped and its photoelectric charge detected by a source/drain channel in a transistor. Such a transistor photodetector can be useful for flagging the safe arrival of a photon in a quantum repeater. The electron trap can be photo-ionized and repeatedly reset for the arrival of successive individual photons. This single photoelectron transistor (SPT) operating at the lambda = 1.3 mu m tele-communication band, was demonstrated by using a windowed-gate double-quantum-well InGaAs/InAlAs/InP heterostructure that was designed to provide near-zero electron g-factor. The g-factor engineering allows selection rules that would convert a photon's polarization to an electron spin polarization. The safe arrival of the photo-electric charge would trigger the commencement of the teleportation algorithm.

  1. SEMICONDUCTOR DEVICES: Humidity sensitive organic field effect transistor

    Science.gov (United States)

    Murtaza, I.; Karimov, Kh S.; Ahmad, Zubair; Qazi, I.; Mahroof-Tahir, M.; Khan, T. A.; Amin, T.

    2010-05-01

    This paper reports the experimental results for the humidity dependent properties of an organic field effect transistor. The organic field effect transistor was fabricated on thoroughly cleaned glass substrate, in which the junction between the metal gate and the organic channel plays the role of gate dielectric. Thin films of organic semiconductor copper phthalocynanine (CuPc) and semitransparent Al were deposited in sequence by vacuum thermal evaporation on the glass substrate with preliminarily deposited Ag source and drain electrodes. The output and transfer characteristics of the fabricated device were performed. The effect of humidity on the drain current, drain current-drain voltage relationship, and threshold voltage was investigated. It was observed that humidity has a strong effect on the characteristics of the organic field effect transistor.

  2. Effects on focused ion beam irradiation on MOS transistors

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, A.N.; Peterson, K.A.; Fleetwood, D.M.; Soden, J.M.

    1997-04-01

    The effects of irradiation from a focused ion beam (FIB) system on MOS transistors are reported systematically for the first time. Three MOS transistor technologies, with 0.5, 1, and 3 {mu}m minimum feature sizes and with gate oxide thicknesses ranging from 11 to 50 nm, were analyzed. Significant shifts in transistor parameters (such as threshold voltage, transconductance, and mobility) were observed following irradiation with a 30 keV Ga{sup +} focused ion beam with ion doses varying by over 5 orders of magnitude. The apparent damage mechanism (which involved the creation of interface traps, oxide trapped charge, or both) and extent of damage were different for each of the three technologies investigated.

  3. Study of current instabilities in high resistivity gallium arsenide; Etude des instabilites de courant dans l'arseniure de gallium de haute resistivite

    Energy Technology Data Exchange (ETDEWEB)

    Barraud, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    We have shown the existence and made a study of the current oscillations produced in high-resistivity gallium arsenide by a strong electric field. The oscillations are associated with the slow travelling of a region of high electrical field across the whole sample. An experimental study of the properties of these instabilities has made it possible for us to distinguish this phenomenon from the Gunn effect, from acoustic-electric effects and from contact effects. In order to account for this type of instability, a differential trapping mechanism involving repulsive impurities is proposed; this mechanism can reduce the concentration of charge carriers in the conduction band at strong electrical fields and can lead to the production of a high-field domain. By developing this model qualitatively we have been able to account for all the properties of high-resistance gallium arsenide crystals subjected to a strong electrical field: increase of the Hall constant, existence of a voltage threshold for these oscillations, production of domains of high field, low rate of propagation of these domains, and finally the possibility of inverting the direction of the propagation of the domain without destroying the latter. A quantitative development of the model makes it possible to calculate the various characteristic parameters of these instabilities. Comparison with experiment shows that there is a good agreement, the small deviations coming especially from the lack of knowledge concerning transport properties in gallium arsenide subjected to high fields. From a study of this model, it appears that the instability phenomenon can occur over a wide range of repulsive centre concentrations, and also for a large range of resistivities. This is the reason why it appears systematically in gallium arsenide of medium and high resistivity. (authors) [French] Nous avons mis en evidence et etudie des oscillations de courant qui se produisent a champ electrique eleve dans l

  4. Superconductivity in Ti-doped iron-arsenide compound Sr4Cr0.8Ti1.2O6Fe2As2

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Superconductivity was achieved in Ti-doped iron-arsenide compound Sr4Cr0.8Ti1.2O6Fe2As2 (abbreviated as Cr-FeAs-42622). The X-ray diffraction measurement shows that this material has a layered structure with the space group of P4/nmm,and with the lattice constants a = b = 3.9003  and c = 15.8376 . Clear diamagnetic signals in ac susceptibility data and zero-resistance in resistivity data were detected at about 6 K,confirming the occurrence of bulk superconductivity. Meanwhile we observed a supercon-ducting transition in the resistive data with the onset transition temperature at 29.2 K,which may be induced by the nonuniform distribution of the Cr/Ti content in the FeAs-42622 phase.

  5. Silicon nanowire field effect transistor for biosensing

    Science.gov (United States)

    Chen, Yu

    Detection and recognition of chemical ions and biological molecules are important in basic science as well as in pharmacology and medicine. Nanotechnology has made it possible to greatly enhance detection sensitivity through the use of nanowires, nanotubes, nanocrystals, nanocantilevers, and quantum dots as sensing platforms. In this work silicon nanowires are used as the conductance channel between the source and drain of a FET (field effect transistor) device and the biomolecular binding on the surface of nanowire modifies the conductance like a change in gate voltage. Due to the high surface-to-volume ratio and unique character of the silicon nanowires, this device has significant advantages in real-time, label-free and highly sensitive detection of a wide range of species, including proteins, nucleic acids and other small molecules. Here we present a biosensor fabricated from CMOS (complementary metal-oxide-semiconductor) compatible top-down methods including electron beam lithography. This method enables scalable manufacturing of multiple sensor arrays with high efficiency. In a systematic study of the device characteristics with different wire widths, we have found the sensitivity of the device increases when wire width decreases. By operating the device in appropriate bias region, the sensitivity of the device can be improved without doping or high temperature annealing. Not only can this device be used to detect the concentration of proteins and metabolites like urea or glucose, but also dynamic information like the dissociation constant can be extracted from the measurement. The device is also used to detect the clinically related cancer antigen CA 15.3 and shows potential application in cancer studies.

  6. Activation Energy of Polycrystalline Silicon Thin Film Transistor

    Directory of Open Access Journals (Sweden)

    B.P. Tyagi

    2011-01-01

    Full Text Available The activation energy of a poly-Si thin film transistor is observed to be influenced by the grain size, trap state density and the inversion layer thickness. The present study aims to investigate these parameters theoretically so as to explore optimum conditions for the working of a polycrystalline silicon thin film transistor. Our computations have revealed that the activation energy decreases with the increase of gate bias for all values of grain size, trap states density and the inversion layer thickness. These findings are compared with the experimental results.

  7. Nanophotonic quantum computer based on atomic quantum transistor

    Science.gov (United States)

    Andrianov, S. N.; Moiseev, S. A.

    2015-10-01

    We propose a scheme of a quantum computer based on nanophotonic elements: two buses in the form of nanowaveguide resonators, two nanosized units of multiatom multiqubit quantum memory and a set of nanoprocessors in the form of photonic quantum transistors, each containing a pair of nanowaveguide ring resonators coupled via a quantum dot. The operation modes of nanoprocessor photonic quantum transistors are theoretically studied and the execution of main logical operations by means of them is demonstrated. We also discuss the prospects of the proposed nanophotonic quantum computer for operating in high-speed optical fibre networks.

  8. Charge sensitivity of superconducting single-electron transistor

    Science.gov (United States)

    Korotkov, Alexander N.

    1996-10-01

    It is shown that the noise-limited charge sensitivity of a single-electron transistor using superconductors (of either SISIS- or NISIN-type) operating near the threshold of quasiparticle tunneling, can be considerably higher than that of a similar transistor made of normal metals or semiconductors. The reason is that the superconducting energy gap, in contrast to the Coulomb blockade, is not smeared by the finite temperature. We also discuss the increase of the maximum operation temperature due to superconductivity and the peaklike features on the I-V curve of SISIS structures.

  9. Copper oxide transistor on copper wire for e-textile

    Science.gov (United States)

    Han, Jin-Woo; Meyyappan, M.

    2011-05-01

    A Cu2O-based field effect transistor was fabricated on Cu wire. Thermal oxidation of Cu forms Cu-Cu2O core-shell structure, where the metal-semiconductor Schottky junction was used as a gate barrier with Pt Ohmic contacts for source and drain. The device was coated with polydimethylsiloxane (PDMS) to protect from contamination and demonstrated as a humidity sensor. The cylindrical structure of the Cu wire and the transistor function enable embedding of simple circuits into textile which can potentially offer smart textile for wearable computing, environmental sensing, and monitoring of human vital signs.

  10. Observation of negative differential transconductance in tunneling emitter bipolar transistors

    Science.gov (United States)

    van Veenhuizen, Marc J.; Locatelli, Nicolas; Moodera, Jagadeesh; Chang, Joonyeon

    2009-08-01

    We report on measurement of negative differential transconductance (NDTC) of iron (Fe)/magnesium-oxide (MgO)/silicon tunneling emitter NPN bipolar transistors. Device simulations reveal that the NDTC is a consequence of an inversion layer at the tunneling-oxide/P-silicon interface for low base voltages. Electrons travel laterally through the inversion layer into the base and give rise to an increase in collector current. The NDTC results from the recombination of those electrons at the interface between emitter and base contact which is dependent on the base voltage. For larger base voltages, the inversion layer disappears marking the onset of normal bipolar transistor behavior.

  11. ELDRS and dose-rate dependence of vertical NPN transistor

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yu-Zhan; LU Wu; REN Di-Yuan; WANG Gai-Li; YU Xue-Feng; GUO Qi

    2009-01-01

    The enhanced low-dose-rate sensitivity (ELDRS) and dose-rate dependence of vertical NPN transistors are investigated in this article.The results show that the vertical NPN transistors exhibit more degradation at low dose rate,and that this degradation is attributed to the increase on base current.The oxide trapped positive charge near the SiO2-Si interface and interface traps at the interface can contribute to the increase on base current and the two-stage hydrogen mechanism associated with space charge effect can well explain the experimental results.

  12. Characterization of a Common-Source Amplifier Using Ferroelectric Transistors

    Science.gov (United States)

    Hunt, Mitchell; Sayyah, Rana; MacLeond, Todd C.; Ho, Pat D.

    2010-01-01

    This paper presents empirical data that was collected through experiments using a FeFET in the established common-source amplifier circuit. The unique behavior of the FeFET lends itself to interesting and useful operation in this widely used common-source amplifier. The paper examines the effect of using a ferroelectric transistor for the amplifier. It also examines the effects of varying load resistance, biasing, and input voltages on the output signal and gives several examples of the output of the amplifier for a given input. The difference between a commonsource amplifier using a ferroelectric transistor and that using a MOSFET is addressed.

  13. Recent progress in photoactive organic field-effect transistors

    OpenAIRE

    Yutaka Wakayama; Ryoma Hayakawa; Hoon-Seok Seo

    2014-01-01

    Recent progress in photoactive organic field-effect transistors (OFETs) is reviewed. Photoactive OFETs are divided into light-emitting (LE) and light-receiving (LR) OFETs. In the first part, LE-OFETs are reviewed from the viewpoint of the evolution of device structures. Device performances have improved in the last decade with the evolution of device structures from single-layer unipolar to multi-layer ambipolar transistors. In the second part, various kinds of LR-OFETs are featured. These ar...

  14. Indium Arsenide Nanowires

    DEFF Research Database (Denmark)

    Madsen, Morten Hannibal

    This thesis is about growth of Au-assisted and self-assisted InAs nanowires (NWs). The wires are synthesized using a solid source molecular beam epitaxy (MBE) system and characterized with several techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM) and ...

  15. Gallium arsenide pixel detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bates, R.; DaVia, C.; O`Shea, V.; Raine, C.; Smith, K. [Glasgow Univ. (United Kingdom). Dept. of Physics and Astronomy; Campbell, M.; Cantatore, E.; Heijne, E.M.; Middelkamp, P.; Ropotar, I.; Scharfetter, L.; Snoeys, W. [CERN, ECP Div., CH-1211 Geneva 23 (Switzerland); D`Auria, S.; Papa, C. del [Department of Physics, University of Udine and INFN Trieste, Via delle Scienze 208, I-33100 Udine (Italy); RD8 Collaboration

    1998-06-01

    GaAs detectors can be fabricated with bidimensional single-sided electrode segmentation. They have been successfully bonded using flip-chip technology to the Omega-3 silicon read-out chip. We present here the design features of the GaAs pixel detectors and results from a test performed at the CERN SpS with a 120 GeV {pi}{sup -} beam. The detection efficiency was 99.2% with a nominal threshold of 5000 e{sup -}. (orig.) 10 refs.

  16. Enhancement of Transistor-to-Transistor Variability Due to Total Dose Effects in 65-nm MOSFETs

    CERN Document Server

    Gerardin, S; Cornale, D; Ding, L; Mattiazzo, S; Paccagnella, A; Faccio, F; Michelis, S

    2015-01-01

    We studied device-to-device variations as a function of total dose in MOSFETs, using specially designed test structures and procedures aimed at maximizing matching between transistors. Degradation in nMOSFETs is less severe than in pMOSFETs and does not show any clear increase in sample-to-sample variability due to the exposure. At doses smaller than 1 Mrad( SiO2) variability in pMOSFETs is also practically unaffected, whereas at very high doses-in excess of tens of Mrad( SiO2)-variability in the on-current is enhanced in a way not correlated to pre-rad variability. The phenomenon is likely due to the impact of random dopant fluctuations on total ionizing dose effects.

  17. Thermal analytic model of current gain for bipolar junction transistor-bipolar static induction transistor compound device

    Institute of Scientific and Technical Information of China (English)

    Zhang You-Run; Zhang Bo; Li Ze-Hong; Lai Chang-Jin; Li Zhao-Ji

    2009-01-01

    This paper proposes a thermal analytical model of current gain for bipolar junction transistor-bipolar static induction transistor (BJT-BSIT) compound device in the low current operation. It also proposes a best thermal compensating factor to the compound device that indicates the relationship between the thermal variation rate of current gain and device structure. This is important for the design of compound device to be optimized. Finally, the analytical model is found to be in good agreement with numerical simulation and experimental results. The test results demonstrate that thermal variation rate of current gain is below 10% in 25℃C-85℃ and 20% in -55℃-25℃.

  18. Semiconductor data book characteristics of approx. 10,000 transistors, FETs, UJTs, diodes, rectifiers, optical semiconductors, triacs and SCRs

    CERN Document Server

    Ball, A M

    1981-01-01

    Semiconductor Data Book, 11th Edition presents tables for ratings and characteristics of transistors and multiple transistors; silicon field effect transistors; unijunction transistors; low power-, variable-, power rectifier-, silicon reference-, and light emitting diodes; photodetectors; triacs; thyristors; lead identification; and transistor comparable types. The book starts by providing an introduction and explanation of tables and manufacturers' codes and addresses. Professionals requiring such data about semiconductors will find the book useful.

  19. Modeling quantization effects in field effect transistors

    International Nuclear Information System (INIS)

    Numerical simulation in the field of semiconductor device development advanced to a valuable, cost-effective and flexible facility. The most widely used simulators are based on classical models, as they need to satisfy time and memory constraints. To improve the performance of field effect transistors such as MOSFETs and HEMTs these devices are continuously scaled down in their dimensions. Consequently the characteristics of such devices are getting more and more determined by quantum mechanical effects arising from strong transversal fields in the channel. In this work an approach based on a two-dimensional electron gas is used to describe the confinement of the carriers. Quantization is considered in one direction only. For the derivation of a one-dimensional Schroedinger equation in the effective mass framework a non-parabolic correction for the energy dispersion due to Kane is included. For each subband a non-parabolic dispersion relation characterized by subband masses and subband non-parabolicity coefficients is introduced and the parameters are calculated via perturbation theory. The method described in this work has been implemented in a software tool that performs a self-consistent solution of Schroedinger- and Poisson-equation for a one-dimensional cut through a MOS structure or heterostructure. The calculation of the carrier densities is performed assuming Fermi-Dirac statistics. In the case of a MOS structure a metal or a polysilicon gate is considered and an arbitrary gate bulk voltage can be applied. This allows investigating quantum mechanical effects in capacity calculations, to compare the simulated data with measured CV curves and to evaluate the results obtained with a quantum mechanical correction for the classical electron density. The behavior of the defined subband parameters is compared to the value of the mass and the non-parabolicity coefficient from the model due to Kane. Finally the presented characterization of the subbands is applied

  20. Relating hysteresis and electrochemistry in graphene field effect transistors

    NARCIS (Netherlands)

    Veligura, Alina; Zomer, Paul J.; Vera-Marun, Ivan J.; Jozsa, Csaba; Gordiichuk, Pavlo I.; van Wees, Bart J.

    2011-01-01

    Hysteresis and commonly observed p-doping of graphene based field effect transistors (FETs) have been discussed in reports over the last few years. However, the interpretation of experimental works differs; and the mechanism behind the appearance of the hysteresis and the role of charge transfer bet

  1. Ambipolar all-polymer bulk heterojunction field-effect transistors

    NARCIS (Netherlands)

    Szendrei, Krisztina; Jarzab, Dorota; Chen, Zhihua; Facchetti, Antonio; Loi, Maria A.

    2010-01-01

    We demonstrate solution processable all-polymer based field-effect transistors (FETs) exhibiting comparable electron and hole mobilities. The semiconducting layer is a bulk heterojunction of poly{[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)}

  2. Transistor biased amplifier minimizes diode discriminator threshold attenuation

    Science.gov (United States)

    Larsen, R. N.

    1967-01-01

    Transistor biased amplifier has a biased diode discriminator driven by a high impedance /several megohms/ current source, rather than a voltage source with several hundred ohms output impedance. This high impedance input arrangement makes the incremental impedance of the threshold diode negligible relative to the input impedance.

  3. Electron properties of fluorinated single-layer graphene transistors

    OpenAIRE

    Withers, Freddie; Dubois, Marc; Savchenko, Alexander K.

    2010-01-01

    We have fabricated transistor structures using fluorinated single-layer graphene flakes and studied their electronic properties at different temperatures. Compared with pristine graphene, fluorinated graphene has very large and strongly temperature dependent resistance in the electro-neutrality region. We show that fluorination creates a mobility gap in graphene's spectrum where electron transport takes place via localised electron states.

  4. Emitter space charge layer transit time in bipolar junction transistors

    Science.gov (United States)

    Rustagi, S. C.; Chattopadhyaya, S. K.

    1981-04-01

    The charge defined emitter space charge layer transit times of double diffused transistors have been calculated using a regional approach, and compared with the corresponding base transit times. The results obtained for emitter space-charge layer transit times have been discussed with reference to the capacitance analysis of Morgan and Smit (1960) for graded p-n junctions.

  5. Conducted EMI in Inverters with SiC Transistors

    NARCIS (Netherlands)

    Gong, X.

    2013-01-01

    Conducted EMI in Inverters with SiC Transistors Electromagnetic Interference (EMI) is the main side effect accompanied with the fast voltage and current switching transients in power electronics applications. Compliance of the Electromagnetic Compatibility (EMC) standard is prescribed for any power

  6. Durable chemical sensors based on field-effect transistors

    NARCIS (Netherlands)

    Reinhoudt, D.N.

    1995-01-01

    The design of durable chemical sensors based on field-effect transistors (FETs) is described. After modification of an ion-sensitive FET (ISFET) with a polysiloxane membrane matrix, it is possible to attach all electroactive components covalently. Preliminary results of measurements with a sodium-se

  7. Single event burnout sensitivity of embedded field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Koga, R.; Crain, S.H.; Crawford, K.B.; Yu, P.; Gordon, M.J.

    1999-12-01

    Observations of single event burnout (SEB) in embedded field effect transistors are reported. Both SEB and other single event effects are presented for several pulse width modulation and high frequency devices. The microscope has been employed to locate and to investigate the damaged areas. A model of the damage mechanism based on the results so obtained is described.

  8. Charge transport in disordered organic field-effect transistors

    NARCIS (Netherlands)

    Tanase, C; Blom, PWM; Meijer, EJ; de Leeuw, DM; Jabbour, GE; Carter, SA; Kido, J; Lee, ST; Sariciftci, NS

    2002-01-01

    The transport properties of poly(2,5-thienylene vinylene) (PTV) field-effect transistors (FET) have been investigated as a function of temperature under controlled atmosphere. In a disordered semiconductor as PTV the charge carrier mobility, dominated by hopping between localized states, is dependen

  9. Low-frequency noise in single electron tunneling transistor

    DEFF Research Database (Denmark)

    Tavkhelidze, A.N.; Mygind, Jesper

    1998-01-01

    The noise in current biased aluminium single electron tunneling (SET) transistors has been investigated in the frequency range of 5 mHz

  10. Flexible carbon-based ohmic contacts for organic transistors

    Science.gov (United States)

    Brandon, Erik (Inventor)

    2007-01-01

    The present invention relates to a system and method of organic thin-film transistors (OTFTs). More specifically, the present invention relates to employing a flexible, conductive particle-polymer composite material for ohmic contacts (i.e. drain and source).

  11. Reference field effect transistor based on chemically modified ISFETs

    NARCIS (Netherlands)

    Skowronska-Ptasinska, Maria; Wal, van der Peter D.; Berg, van den Albert; Bergveld, Piet; Sudhölter, Ernst J.R.; Reinhoudt, David N.

    1990-01-01

    Different hydrophobic polymers were used for chemical modification of ion-sensitive field effect transistors (ISFETs) in order to prepare a reference FET (REFET). Chemical attachment of the polymer to the ISFET gate results in a long lifetime of the device. Properties of polyacrylate (polyACE) REFET

  12. Field-Induced Superconductivity in Electric Double Layer Transistors

    NARCIS (Netherlands)

    Ueno, Kazunori; Shimotani, Hidekazu; Yuan, Hongtao; Ye, Jianting; Kawasaki, Masashi; Iwasa, Yoshihiro

    2014-01-01

    Electric field tuning of superconductivity has been a long-standing issue in solid state physics since the invention of the field-effect transistor (FET) in 1960. Owing to limited available carrier density in conventional FET devices, electric-field-induced superconductivity was believed to be possi

  13. A high current, high speed pulser using avalanche transistors

    International Nuclear Information System (INIS)

    A high current, high speed pulser for the beam pulsing of a linear accelerator is described. It uses seven avalanche transistors in cascade. Design of a trigger circuit to obtain fast rise time is discussed. The characteristics of the pulser are : (a) Rise time = 0.9 ns (FWHM) and (d) Life time asymptotically equals 2000 -- 3000 hr (at 50 Hz). (author)

  14. Reconfigurable Threshold Logic Element with SET and MOS Transistors

    Institute of Scientific and Technical Information of China (English)

    WEI Rong-Shan; CHEN Jin-Feng; CHEN Shou-Chang; HE Ming-Hua

    2012-01-01

    A novel reconfigurable threshold logic element (TLE) using single-electron transistors (SETs) and metal-oxide semiconductor (MOS) transistors is proposed.The proposed TLE is highly reconfigurable,which can perform all two-variable logic functions directly or indirectly,including OR,NOR,AND,NAND,XOR and XNOR.The reconfiguration of the TLE is realized by simply configuring the input bits without changing the device parameters.The design methodology can also be applied in the design of a multi-variable TLE.The reconfigurable TLE demonstrates good performance at room temperature with a compact structure and ultralow power dissipation.The reconfigurable TLE can be useful in high-density high-performance reconfigurable systems and artificial neural networks.%A novel reconfigurable threshold logic element (TLE) using single-electron transistors (SETs) and metal-oxide-semiconductor (MOS) transistors is proposed. The proposed TLE is highly reconfigurable, which can perform all two-variable logic functions directly or indirectly, including OR, NOR, AND, NAND, XOR and XNOR. The reconfiguration of the TLE is realized by simply configuring the input bits without changing the device parameters. The design methodology can also be applied in the design of a multi-variable TLE. The reconfigurable TLE demonstrates good performance at room temperature with a compact structure and ultralow power dissipation. The reconfigurable TLE can be useful in high-density high-performance reconfigurable systems and artificial neural networks.

  15. π-Conjugated Organic Semiconductors for Field-Effect Transistors

    Institute of Scientific and Technical Information of China (English)

    LIU Yun-qi

    2005-01-01

    @@ 1Results and Discussion Organic semiconductors employed as active layers in field-effect transistors (FETs) are of great current interest because such FETs can potentially be fabricated at low cost, over large areas, and on flexible substrates. Such facile fabrication approaches offer a significant advantage over silicon technology in numerous applications.

  16. Conductance switching in organic ferroelectric field-effect transistors

    NARCIS (Netherlands)

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

    2011-01-01

    Staggered bottom-contact top-gate organic ferroelectric field-effect transistors are fabricated with poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) as ferroelectric gate and poly[bis(4-phenyl)(2,4,6- trimethylphenyl)amine] as semiconductor. Polarization reversal of the ferroelectric gate

  17. Metal-nanoparticle single-electron transistors fabricated using electromigration

    DEFF Research Database (Denmark)

    Bolotin, K I; Kuemmeth, Ferdinand; Pasupathy, A N;

    2004-01-01

    We have fabricated single-electron transistors from individual metal nanoparticles using a geometry that provides improved coupling between the particle and the gate electrode. This is accomplished by incorporating a nanoparticle into a gap created between two electrodes using electromigration, all...

  18. Ultrathin regioregular poly(3-hexyl thiophene) field-effect transistors

    DEFF Research Database (Denmark)

    Sandberg, H.G.O.; Frey, G.L.; Shkunov, M.N.;

    2002-01-01

    Ultrathin films of regioregular poly(3-hexyl thiophene) (RR-P3HT) were deposited through a dip-coating technique and utilized as the semiconducting film in field-effect transistors (FETs). Proper selection of the substrate and solution concentration enabled the growth of a monolayer-thick RR-P3HT...

  19. Effects of overheating in a single-electron transistor

    DEFF Research Database (Denmark)

    Korotkov, A. N.; Samuelsen, Mogens Rugholm; Vasenko, S. A.

    1994-01-01

    Heating of a single-electron transistor (SET) caused by the current flowing through it is considered. The current and the temperature increase should be calculated self-consistently taking into account various paths of the heat drain. Even if there is no heat drain from the central electrode...

  20. Electrical interfacing of neurotransmitter receptor and field effect transistor

    Science.gov (United States)

    Peitz, I.; Fromherz, P.

    2009-10-01

    The interfacing of a ligand-gated ion channel to a transistor is studied. It relies on the transduction of ion current to a voltage in a cell-transistor junction. For the first time, a genetically modified cell is used without external driving voltage as applied by a patch-pipette. Using a core-coat conductor model, we show that an autonomous dynamics gives rise to a signal if a driving voltage is provided by potassium channels, and if current compensation is avoided by an inhomogeneous activation of channels. In a proof-of-principle experiment, we transfect HEK293 cells with the serotonin receptor 5-HT3A and the potassium channel Kv1.3. The interfacing is characterized under voltage-clamp with a negative transistor signal for activated 5-HT3A and a positive signal for activated Kv1.3. Without patch-pipette, a biphasic transient is induced by serotonin. The positive wave is assigned to 5-HT3A receptors in the free membrane that drive a potassium outward current through the adherent membrane. The negative wave is attributed to 5-HT3A receptors in the adherent membrane that are activated with a delay due to serotonin diffusion. The implementation of a receptor-cell-transistor device is a fundamental step in the development of biosensors that combine high specificity and universal microelectronic readout.

  1. Carbon nanotube thin film transistors based on aerosol methods

    International Nuclear Information System (INIS)

    We demonstrate a fabrication method for high-performance field-effect transistors (FETs) based on dry-processed random single-walled carbon nanotube networks (CNTNs) deposited at room temperature. This method is an advantageous alternative to solution-processed and direct CVD grown CNTN FETs, which allows using various substrate materials, including heat-intolerant plastic substrates, and enables an efficient, density-controlled, scalable deposition of as-produced single-walled CNTNs on the substrate directly from the aerosol (floating catalyst) synthesis reactor. Two types of thin film transistor (TFT) structures were fabricated to evaluate the FET performance of dry-processed CNTNs: bottom-gate transistors on Si/SiO2 substrates and top-gate transistors on polymer substrates. Devices exhibited on/off ratios up to 105 and field-effect mobilities up to 4 cm2 V-1 s-1. The suppression of hysteresis in the bottom-gate device transfer characteristics by means of thermal treatment in vacuum and passivation by an atomic layer deposited Al2O3 film was investigated. A 32 nm thick Al2O3 layer was found to be able to eliminate the hysteresis.

  2. Performance and processability of organic field effect transistors

    OpenAIRE

    Alt, Milan

    2015-01-01

    The present work addresses challenges with the performance and processability of organic semiconductors for their application in organic field-effect transistors (OFET). The results that are presented in this thesis show that combining advances in chemical material design and interface tailoring with advances in deposition and processing techniques, in order to unfold the potential of organic electronics, is a matter of engineering.

  3. Physics of organic ferroelectric field-effect transistors

    NARCIS (Netherlands)

    Brondijk, Jakob J.; Asadi, Kamal; Blom, Paul W. M.; de Leeuw, Dago M.

    2012-01-01

    Most of the envisaged applications of organic electronics require a nonvolatile memory that can be programmed, erased, and read electrically. Ferroelectric field-effect transistors (FeFET) are especially suitable due to the nondestructive read-out and low power consumption. Here, an analytical model

  4. Computer simulation of the scaled power bipolar SHF transistor structures

    Science.gov (United States)

    Nelayev, V. V.; Efremov, V. A.; Snitovsky, Yu. P.

    2007-04-01

    New advanced technology for creation of the npn power silicon bipolar SHF transistor structure is proposed. Preferences of the advanced technology in comparison with standard technology are demonstrated. Simulation of both technology flows was performed with emphasis on scaling of the discussed device structure.

  5. Early effect of SiGe heterojunction bipolar transistors

    Science.gov (United States)

    Xu, Xiao-Bo; Zhang, He-Ming; Hu, Hui-Yong; Qu, Jiang-Tao

    2012-06-01

    The standard Early voltage of the SGP model is generalized for SiGe NPN heterojunction bipolar transistors (HBTs). A new compact formulation of the Early voltage compatible with the SGP model is presented. The impact of the Ge profile on Early effect is shown and validated by experiments. The model can be applied to the SGP model for circuit simulation.

  6. Graphene transistors with multifunctional polymer brushes for biosensing applications.

    Science.gov (United States)

    Hess, Lucas H; Lyuleeva, Alina; Blaschke, Benno M; Sachsenhauser, Matthias; Seifert, Max; Garrido, Jose A; Deubel, Frank

    2014-06-25

    Exhibiting a combination of exceptional structural and electronic properties, graphene has a great potential for the development of highly sensitive sensors. To date, many challenging chemical, biochemical, and biologic sensing tasks have been realized based on graphene. However, many of these sensors are rather unspecific. To overcome this problem, for instance, the sensor surface can be modified with analyte-specific transducers such as enzymes. One problem associated with the covalent attachment of such biomolecular systems is the introduction of crystal defects that have a deleterious impact on the electronic properties of the sensor. In this work, we present a versatile platform for biosensing applications based on polymer-modified CVD-grown graphene transistors. The functionalization method of graphene presented here allows one to integrate several functional groups within surface-bound polymer brushes without the introduction of additional defects. To demonstrate the potential of this polymer brush functionalization scaffold, we modified solution-gated graphene field-effect transistors with the enzyme acetylcholinesterase and a transducing group, allowing the detection of the neurotransmitter acetylcholine. Taking advantage of the transducing capability of graphene transistors and the versatility of polymer chemistry and enzyme biochemistry, this study presents a novel route for the fabrication of highly sensitive, multipurpose transistor sensors that can find application for a multitude of biologically relevant analytes. PMID:24866105

  7. Organic transistors in optical displays and microelectronic applications

    NARCIS (Netherlands)

    Gelinck, G.H.; Heremans, P.; Nomoto, K.; Anthopoulos, T.D.

    2010-01-01

    Organic thin-film transistors (OTFTs) offer unprecedented opportunities for implementation in a broad range of technological applications spanning from large-volume microelectronics and optical displays to chemical and biological sensors. In this Progress Report, we review the application of organic

  8. Multiple facets of tightly coupled transducer-transistor structures

    Science.gov (United States)

    Heidari, Hadi; Dahiya, Ravinder

    2015-12-01

    The ever increasing demand for data processing requires different paradigms for electronics. Excellent performance capabilities such as low power and high speed in electronics can be attained through several factors including using functional materials, which sometimes acquire superior electronic properties. The transduction-based transistor switching mechanism is one such possibility, which exploits the change in electrical properties of the transducer as a function of a mechanically induced deformation. Originally developed for deformation sensors, the technique is now moving to the centre stage of the electronic industry as the basis for new transistor concepts to circumvent the gate voltage bottleneck in transistor miniaturization. In issue 37 of Nanotechnology, Chang et al show the piezoelectronic transistor (PET), which uses a fast, low-power mechanical transduction mechanism to propagate an input gate voltage signal into an output resistance modulation. The findings by Chang et al will spur further research into piezoelectric scaling, and the PET fabrication techniques needed to advance this type of device in the future.

  9. Experiments with Charge Indicator Based on Bipolar Transistors

    Science.gov (United States)

    Dvorak, Leos; Planinsic, Gorazd

    2012-01-01

    A simple charge indicator with bipolar transistors described recently enables us to perform a number of experiments suitable for high-school physics. Several such experiments are presented and discussed in this paper as well as some features of the indicator important for its use in schools, namely its sensitivity and robustness, i.e. the…

  10. Bipolar Transistors Can Detect Charge in Electrostatic Experiments

    Science.gov (United States)

    Dvorak, L.

    2012-01-01

    A simple charge indicator with bipolar transistors is described that can be used in various electrostatic experiments. Its behaviour enables us to elucidate links between 'static electricity' and electric currents. In addition it allows us to relate the sign of static charges to the sign of the terminals of an ordinary battery. (Contains 7 figures…

  11. Fabrication and characterization of heterojunction transistors

    Science.gov (United States)

    Lo, Chien-Fong

    2011-12-01

    Submircon emitter finger high-speed double heterojunction InAlAs/InGaAsSb/InGaAs bipolar transistors (DHBTs) and a variety of nitride high electron mobility transistors (HEMTs) including AlGaN/GaN, InAlN/GaN, and AlN/GaN were fabricated and characterized. DHBT structures were grown by solid source molecular beam epitaxy (SSMBE) on Fe-doped semiinsulating InP substrates and nitride HEMTs were grown with a metal organic chemical vapor deposition (MOCVD) system on sapphire or SiC substrates. AlN/GaN HEMTs were grown with a RF-VMBE on sapphire substrates. Ultra low base contact resistance of 3.7 x 10-7 ohm-cm2 after 1 min 250¢XC thermal treatment on noval InGaAsSb base of DHBTs was achieved and a long-term thermal stability of base metallization was studied. Regarding small scale DHBT fabrication, tri-layer system was introduced to improve the resolution for submicron emitter patterning and help to pile up a thicker emitter metal stack; guard-ring technique was applied around the emitter periphery in order to preserve the current gain at small emitter dimensions. Ultra low turn-on voltage and high current gain can be realized with InGaAsSb-base DHBTs as compared to the conventional InGaAs-base DHBTs. A peak current gain cutoff frequency (fT) of 268 GHz and power gain cutoff frequency (fmax) of 485 GHz were achieved. GaN-based HEMTs herein were fabricated with gate lengths from 400 nm to 1im, and were deposited Ti/Al/Ni/Au as their Ohmic contact metallization. Effects of the Ohmic contact annealing for lattice-matched InAlN/GaN HEMTs with and without a thin GaN cap layer were exhibited and their optimal annealing temperature were obtained. A maximum drain current of 1.3 A/mm and an extrinsic transconductance of 366 mS/mm were demonstrated for InAlN/GaN HEMTs with the shortest gate length. A unity-gain cutoff frequency (fT) of 69 GHz and a maximum frequency of oscillation (fmax) of 80 GHz for InAlN/GaN HEMTs were extracted from measured scattering parameters

  12. Silicon Carbide Technologies for High Temperature Motor Drives

    OpenAIRE

    Snefjellå, Øyvind Holm

    2011-01-01

    Many applications benefit from using converters which can operate at high temperatures among them; down-hole drilling, hybrid vehicles and space craft. The theoretical performance of transistors made of Silicon Carbide (SiC) is investigated in this work. It is shown that their properties at high temperatures are superior compared to Silicon (Si) devices. Two half-bridge converters, using SiC normally-off Junction Field Effect Transistors (JFET) and SiC Bipolar Junction Transistors (BJT), are ...

  13. Total dose effects on the matching properties of deep submicron MOS transistors

    International Nuclear Information System (INIS)

    Based on 0.18 μm MOS transistors, for the first time, the total dose effects on the matching properties of deep submicron MOS transistors are studied. The experimental results show that the total dose radiation magnifies the mismatch among identically designed MOS transistors. In our experiments, as the radiation total dose rises to 200 krad, the threshold voltage and drain current mismatch percentages of NMOS transistors increase from 0.55% and 1.4% before radiation to 17.4% and 13.5% after radiation, respectively. PMOS transistors seem to be resistant to radiation damage. For all the range of radiation total dose, the threshold voltage and drain current mismatch percentages of PMOS transistors keep under 0.5% and 2.72%, respectively. (semiconductor devices)

  14. Performance Analysis of Silicon and Germanium Nanowire Transistor using Crystal Orientation and Oxide Thickness

    OpenAIRE

    P.Theres Mary; N.B. BALAMURUGAN

    2014-01-01

    Nanowire Transistors have attracted attention due to the probable high performance and excellent controllability of device current. In this paper, we investigate the performance analysis of nanowire transistors made of silicon and germanium materials. The nanowire transistor has a 3D distribution of electron density and electrostatic potential, therefore self-consistent 3D simulations are used. Nanowire (tool) is 3D Poisson self-consistent simulator which can study the 3D transport in nanowir...

  15. Optimisation of trench isolated bipolar transistors on SOI substrates by 3D electro-thermal simulations

    Science.gov (United States)

    Nigrin, S.; Armstrong, G. A.; Kranti, A.

    2007-09-01

    This paper provides a comprehensive analysis of thermal resistance of trench isolated bipolar transistors on SOI substrates based on 3D electro-thermal simulations calibrated to experimental data. The impact of emitter length, width, spacing and number of emitter fingers on thermal resistance is analysed in detail. The results are used to design and optimise transistors with minimum thermal resistance and minimum transistor area.

  16. Thin film transistors for displays on plastic substrates

    Science.gov (United States)

    Lee, M. J.; Judge, C. P.; Wright, S. W.

    2000-08-01

    We have successfully made thin film transistors on transparent, flexible polymer substrates. These transistors have electrical properties suitable for driving the pixels in active matrix liquid crystal displays and also for building integrated row driver circuits. The devices are fabricated on polyethylene naphthalate using a low temperature CdSe process at a maximum temperature of 150°C, by evaporation and radio frequency sputtering onto unheated substrates, with pattern definition using standard photolithography and etching. Electrical properties achieved include carrier field effect mobilities of >30 cm 2/V s, threshold voltages of ˜2 V, switching ratio >10 6, an off-state leakage current of 1 μA with a gate voltage swing of electrical properties were found to scale with device channel length and width.

  17. Polarity control in WSe2 double-gate transistors

    Science.gov (United States)

    Resta, Giovanni V.; Sutar, Surajit; Balaji, Yashwanth; Lin, Dennis; Raghavan, Praveen; Radu, Iuliana; Catthoor, Francky; Thean, Aaron; Gaillardon, Pierre-Emmanuel; de Micheli, Giovanni

    2016-01-01

    As scaling of conventional silicon-based electronics is reaching its ultimate limit, considerable effort has been devoted to find new materials and new device concepts that could ultimately outperform standard silicon transistors. In this perspective two-dimensional transition metal dichalcogenides, such as MoS2 and WSe2, have recently attracted considerable interest thanks to their electrical properties. Here, we report the first experimental demonstration of a doping-free, polarity-controllable device fabricated on few-layer WSe2. We show how modulation of the Schottky barriers at drain and source by a separate gate, named program gate, can enable the selection of the carriers injected in the channel, and achieved controllable polarity behaviour with ON/OFF current ratios >106 for both electrons and holes conduction. Polarity-controlled WSe2 transistors enable the design of compact logic gates, leading to higher computational densities in 2D-flatronics. PMID:27390014

  18. Fullerene thin-film transistors fabricated on polymeric gate dielectric

    Energy Technology Data Exchange (ETDEWEB)

    Puigdollers, J. [Micro and Nano Technology Group (MNT), Dept. Enginyeria Electronica, Universitat Politecnica Catalunya, C/ Jordi Girona 1-3, Modul C4, 08034-Barcelona (Spain)], E-mail: jpuigd@eel.upc.edu; Voz, C. [Micro and Nano Technology Group (MNT), Dept. Enginyeria Electronica, Universitat Politecnica Catalunya, C/ Jordi Girona 1-3, Modul C4, 08034-Barcelona (Spain); Cheylan, S. [ICFO - Mediterranean Technology Park, Avda del Canal Olimpic s/n, 08860-Castelldefels (Spain); Orpella, A.; Vetter, M.; Alcubilla, R. [Micro and Nano Technology Group (MNT), Dept. Enginyeria Electronica, Universitat Politecnica Catalunya, C/ Jordi Girona 1-3, Modul C4, 08034-Barcelona (Spain)

    2007-07-16

    Thin-film transistors with fullerene as n-type organic semiconductor have been fabricated. A polymeric gate dielectric, polymethyl methacrylate, has been used as an alternative to usual inorganic dielectrics. No significant differences in the microstructure of fullerene thin-films grown on polymethyl methacrylate were observed. Devices with either gold or aluminium top electrodes have been fabricated. Although the lower work-function of aluminium compared to gold should favour electron injection, similar field-effect mobilities in the range of 10{sup -2} cm{sup 2} V{sup -1} s{sup -1} were achieved in both cases. Actually, the output characteristics indicate that organic thin-film transistors behave more linearly with gold than with aluminium electrodes. These results confirm that not only energy barriers determine carrier injection at metal/organic interfaces, but also chemical interactions.

  19. A Single-Transistor Active Pixel CMOS Image Sensor Architecture

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guo-An; ZHANG Dong-Wei; HE Jin; SU Yan-Mei; WANG Cheng; CHEN Qin; LIANG Hai-Lang; YE Yun

    2012-01-01

    A single-transistor CMOS active pixel image sensor (1T CMOS APS) architecture is proposed,By switching the photosensing pinned diode,resetting and selecting can be achieved by diode pull-up and capacitive coupling pull-down of the source follower. Thus,the reset and selected transistors can be removed. In addition,the reset and selected signal lines can be shared to reduce the metal signal line,leading to a very high fill factor.The pixel design and operation principles are discussed in detail.The functionality of the proposed 1 T CMOS APS architecture has been experimentally verified using a fabricated chip in a standard 0.35 μm CMOS AMIS technology.

  20. Thin film transistors for flexible electronics: Contacts, dielectrics and semiconductors

    KAUST Repository

    Quevedo-López, Manuel Angel Quevedo

    2011-06-01

    The development of low temperature, thin film transistor processes that have enabled flexible displays also present opportunities for flexible electronics and flexible integrated systems. Of particular interest are possible applications in flexible sensor systems for unattended ground sensors, smart medical bandages, electronic ID tags for geo-location, conformal antennas, radiation detectors, etc. In this paper, we review the impact of gate dielectrics, contacts and semiconductor materials on thin film transistors for flexible electronics applications. We present our recent results to fully integrate hybrid complementary metal oxide semiconductors comprising inorganic and organic-based materials. In particular, we demonstrate novel gate dielectric stacks and semiconducting materials. The impact of source and drain contacts on device performance is also discussed. Copyright © 2011 American Scientific Publishers.

  1. Capacitance Variation of Electrolyte-Gated Bilayer Graphene Based Transistors

    Directory of Open Access Journals (Sweden)

    Hediyeh Karimi

    2013-01-01

    Full Text Available Quantum capacitance of electrolyte-gated bilayer graphene field-effect transistors is investigated in this paper. Bilayer graphene has received huge attention due to the fact that an energy gap could be opened by chemical doping or by applying external perpendicular electric field. So, this extraordinary property can be exploited to use bilayer graphene as a channel in electrolyte-gated field-effect transistors. The quantum capacitance of bi-layer graphene with an equivalent circuit is presented, and also based on the analytical model a numerical solution is reported. We begin by modeling the DOS, followed by carrier concentration as a function V in degenerate and nondegenerate regimes. To further confirm this viewpoint, the presented analytical model is compared with experimental data, and acceptable agreement is reported.

  2. Organic Light-Emitting Diodes Driven by Organic Transistors

    Institute of Scientific and Technical Information of China (English)

    胡远川; 董桂芳; 王立铎; 梁琰; 邱勇

    2004-01-01

    Organic thin-film field-effect transistors (OTFTs) with pentacene as the semiconductor have been fabricated for driving an organic light-emitting diode (OLED). The driving circuit includes two OTFTs and one storage capacitor. The field-effect mobility of the transistors in the driving circuit is more than 0.3 cm2/Vs, and the on/off ratio is larger than 104. The light-emission area of the OLED is 0. 04mm2 and the brightness is larger than 400cd/m2 when the selected line voltage, data line voltage and drive voltage all are -40 V. The responding characteristics and holding characteristics are also researched when the selected line voltage and the date line voltage are changed.

  3. Modeling and Simulation of Photoelectronic Lambda Bipolar Transistor

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Based on the region model of lambda bipolar transistor (LBT), a dividing region theory model of PLBT is set up,simulated and verified. Firstly, the principal operations of different kinds of photoelectronic lambda bipolar transistor (PLBT) are characterized by a simple circuit model.Through mathematical analysis of the equivalent circuit, the typical characteristics curve is divided into positive resistance, peak, negative resistance and cutoff regions. Secondly, by analyzing and simulating this model, the ratio of MOSFET width to channel length, threshold voltage and common emitter gain are discovered as the main structure parameters that determine the characteristic curves of PLBT. And peak region width, peak current value, negative resistance value and valley voltage value of PLBT can be changed conveniently according to the actual demands by modifying these parameters. Finally comparisons of the characteristics of the fabricated devices and the simulation results are made, which show that the analytical results are in agreement with the observed devices characteristics.

  4. Carbon nanotube transistors with graphene oxide films as gate dielectrics

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Carbon nanomaterials,including the one-dimensional(1-D) carbon nanotube(CNT) and two-dimensional(2-D) graphene,are heralded as ideal candidates for next generation nanoelectronics.An essential component for the development of advanced nanoelectronics devices is processing-compatible oxide.Here,in analogy to the widespread use of silicon dioxide(SiO2) in silicon microelectronic industry,we report the proof-of-principle use of graphite oxide(GO) as a gate dielectrics for CNT field-effect transistor(FET) via a fast and simple solution-based processing in the ambient condition.The exceptional transistor characteristics,including low operation voltage(2 V),high carrier mobility(950 cm2/V-1 s-1),and the negligible gate hysteresis,suggest a potential route to the future all-carbon nanoelectronics.

  5. Vertical Organic Field-Effect Transistors for Integrated Optoelectronic Applications.

    Science.gov (United States)

    Yu, Hyeonggeun; Dong, Zhipeng; Guo, Jing; Kim, Doyoung; So, Franky

    2016-04-27

    Direct integration of a vertical organic field-effect transistor (VOFET) and an optoelectronic device offers a single stacked, low power optoelectronic VOFET with high aperture ratios. However, a functional optoelectronic VOFET could not be realized because of the difficulty in fabricating transparent source and gate electrodes. Here, we report a VOFET with an on/off ratio up to 10(5) as well as output current saturation by fabricating a transparent gate capacitor consisting of a perforated indium tin oxide (ITO) source electrode, HfO2 gate dielectric, and ITO gate electrode. Effects of the pore size and the pore depth within the porous ITO electrodes on the on/off characteristic of a VOFET are systematically explained in this work. By combining a phosphorescent organic light-emitting diode with an optimized VOFET structure, a vertical organic light-emitting transistor with a luminance on/off ratio of 10(4) can be fabricated. PMID:27082815

  6. High mobility solution-processed hybrid light emitting transistors

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Bright; Kim, Jin Young [School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Ullah, Mujeeb; Burn, Paul L.; Namdas, Ebinazar B., E-mail: e.namdas@uq.edu.au, E-mail: seojh@dau.ac.kr [Centre for Organic Photonics and Electronics, University of Queensland, Brisbane, Queensland 4072 (Australia); Chae, Gil Jo [Department of Materials Physics, Dong-A University, Busan 604-714 (Korea, Republic of); Department of Physics and EHSRC, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Cho, Shinuk [Department of Physics and EHSRC, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Seo, Jung Hwa, E-mail: e.namdas@uq.edu.au, E-mail: seojh@dau.ac.kr [Department of Materials Physics, Dong-A University, Busan 604-714 (Korea, Republic of)

    2014-11-03

    We report the design, fabrication, and characterization of high-performance, solution-processed hybrid (inorganic-organic) light emitting transistors (HLETs). The devices employ a high-mobility, solution-processed cadmium sulfide layer as the switching and transport layer, with a conjugated polymer Super Yellow as an emissive material in non-planar source/drain transistor geometry. We demonstrate HLETs with electron mobilities of up to 19.5 cm{sup 2}/V s, current on/off ratios of >10{sup 7}, and external quantum efficiency of 10{sup −2}% at 2100 cd/m{sup 2}. These combined optical and electrical performance exceed those reported to date for HLETs. Furthermore, we provide full analysis of charge injection, charge transport, and recombination mechanism of the HLETs. The high brightness coupled with a high on/off ratio and low-cost solution processing makes this type of hybrid device attractive from a manufacturing perspective.

  7. Solvent vapour detection with a charge flow transistor

    Energy Technology Data Exchange (ETDEWEB)

    Wilkop, T; Ray, A K [Sheffield Hallam University, School of Engineering, Physical Electronics and Fibre Optics Research Laboratories, City Campus, Pond Street, Sheffield (United Kingdom)

    2002-10-21

    A novel method to detect reversibly high concentrations of organic vapours in air has been developed by combining an intrinsically low conductive membrane of the calix[4]resorcinarene [C{sub 7}H{sub 15}] derivative with a charge flow transistor. The modulation of the turn-on response for the transistor upon exposure to acetone, chloroform, methanol, hexane and water is presented. The increase in the membrane conductivity is partially attributed to condensation of the vapours in the highly microporous membrane even below the saturation vapour pressure and partially to the effect of the polar analyte molecules complexing inside and between the OH groups of the cavities. The observed sensitivity is in the order chloroform chloroform >> acetone >> methanol >> hexane >> water.

  8. A Fast Dynamic 64-bit Comparator with Small Transistor Count

    Directory of Open Access Journals (Sweden)

    Chua-Chin Wang

    2002-01-01

    Full Text Available In this paper, we propose a 64-bit fast dynamic CMOS comparator with small transistor count. Major features of the proposed comparator are the rearrangement and re-ordering of transistors in the evaluation block of a dynamic cell, and the insertion of a weak n feedback inverter, which helps the pull-down operation to ground. The simulation results given by pre-layout tools, e.g. HSPICE, and post-layout tools, e.g. TimeMill, reveal that the delay is around 2.5 ns while the operating clock rate reaches 100 MHz. A physical chip is fabricated to verify the correctness of our design by using UMC (United Microelectronics Company 0.5 μm (2P2M technology.

  9. Measurement of ionizing radiation using carbon nanotube field effect transistor

    International Nuclear Information System (INIS)

    Single-walled carbon nanotubes (SWNTs) are a new class of highly promising nanomaterials for future nano-electronics. Here, we present an initial investigation of the feasibility of using SWNT field effect transistors (SWNT-FETs) formed on silicon-oxide substrates and suspended FETs for radiation dosimetry applications. Electrical measurements and atomic force microscopy (AFM) revealed the intactness of SWNT-FET devices after exposure to over 1 Gy of 6 MV therapeutic x-rays. The sensitivity of SWNT-FET devices to x-ray irradiation is elucidated by real-time dose monitoring experiments and accumulated dose reading based on threshold voltage shift. SWNT-FET devices exhibit sensitivities to x-rays that are at least comparable to or orders of magnitude higher than commercial MOSFET (metal-oxide semiconductor field effect transistor) dosimeters and could find applications as miniature dosimeters for microbeam profiling and implantation. (note)

  10. Orientation selectivity in a multi-gated organic electrochemical transistor

    Science.gov (United States)

    Gkoupidenis, Paschalis; Koutsouras, Dimitrios A.; Lonjaret, Thomas; Fairfield, Jessamyn A.; Malliaras, George G.

    2016-06-01

    Neuromorphic devices offer promising computational paradigms that transcend the limitations of conventional technologies. A prominent example, inspired by the workings of the brain, is spatiotemporal information processing. Here we demonstrate orientation selectivity, a spatiotemporal processing function of the visual cortex, using a poly(3,4ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) organic electrochemical transistor with multiple gates. Spatially distributed inputs on a gate electrode array are found to correlate with the output of the transistor, leading to the ability to discriminate between different stimuli orientations. The demonstration of spatiotemporal processing in an organic electronic device paves the way for neuromorphic devices with new form factors and a facile interface with biology.

  11. Laser direct synthesis of silicon nanowire field effect transistors

    International Nuclear Information System (INIS)

    We demonstrate a single-step, laser-based technique to fabricate silicon nanowire field effect transistors. Boron-doped silicon nanowires are synthesized using a laser-direct-write chemical vapor deposition process, which can produce nanowires as small as 60 nm, far below the diffraction limit of the laser wavelength of 395 nm. In addition, the method has the advantages of in situ doping, catalyst-free growth, and precise control of nanowire position, orientation, and length. Silicon nanowires are directly fabricated on an insulating surface and ready for subsequent device fabrication without the need for transfer and alignment, thus greatly simplifying device fabrication processes. Schottky barrier nanowire field effect transistors with a back-gate configuration are fabricated from the laser-direct-written Si nanowires and electrically characterized. (paper)

  12. Polarity control in WSe2 double-gate transistors.

    Science.gov (United States)

    Resta, Giovanni V; Sutar, Surajit; Balaji, Yashwanth; Lin, Dennis; Raghavan, Praveen; Radu, Iuliana; Catthoor, Francky; Thean, Aaron; Gaillardon, Pierre-Emmanuel; de Micheli, Giovanni

    2016-01-01

    As scaling of conventional silicon-based electronics is reaching its ultimate limit, considerable effort has been devoted to find new materials and new device concepts that could ultimately outperform standard silicon transistors. In this perspective two-dimensional transition metal dichalcogenides, such as MoS2 and WSe2, have recently attracted considerable interest thanks to their electrical properties. Here, we report the first experimental demonstration of a doping-free, polarity-controllable device fabricated on few-layer WSe2. We show how modulation of the Schottky barriers at drain and source by a separate gate, named program gate, can enable the selection of the carriers injected in the channel, and achieved controllable polarity behaviour with ON/OFF current ratios >10(6) for both electrons and holes conduction. Polarity-controlled WSe2 transistors enable the design of compact logic gates, leading to higher computational densities in 2D-flatronics. PMID:27390014

  13. Thin film transistors for flexible electronics: contacts, dielectrics and semiconductors.

    Science.gov (United States)

    Quevedo-Lopez, M A; Wondmagegn, W T; Alshareef, H N; Ramirez-Bon, R; Gnade, B E

    2011-06-01

    The development of low temperature, thin film transistor processes that have enabled flexible displays also present opportunities for flexible electronics and flexible integrated systems. Of particular interest are possible applications in flexible sensor systems for unattended ground sensors, smart medical bandages, electronic ID tags for geo-location, conformal antennas, radiation detectors, etc. In this paper, we review the impact of gate dielectrics, contacts and semiconductor materials on thin film transistors for flexible electronics applications. We present our recent results to fully integrate hybrid complementary metal oxide semiconductors comprising inorganic and organic-based materials. In particular, we demonstrate novel gate dielectric stacks and semiconducting materials. The impact of source and drain contacts on device performance is also discussed.

  14. Carbon Nanotubes for Thin Film Transistor: Fabrication, Properties, and Applications

    Directory of Open Access Journals (Sweden)

    Yucui Wu

    2013-01-01

    Full Text Available We review the present status of single-walled carbon nanotubes (SWCNTs for their production and purification technologies, as well as the fabrication and properties of single-walled carbon nanotube thin film transistors (SWCNT-TFTs. The most popular SWCNT growth method is chemical vapor deposition (CVD, including plasma-enhanced chemical vapor deposition (PECVD, floating catalyst chemical vapor deposition (FCCVD, and thermal CVD. Carbon nanotubes (CNTs used to fabricate thin film transistors are sorted by electrical breakdown, density gradient ultracentrifugation, or gel-based separation. The technologies of applying CNT random networks to work as the channels of SWCNT-TFTs are also reviewed. Excellent work from global researchers has been benchmarked and analyzed. The unique properties of SWCNT-TFTs have been reviewed. Besides, the promising applications of SWCNT-TFTs have been explored. Finally, the key issues to be solved in future have been summarized.

  15. Kinase detection with gallium nitride based high electron mobility transistors.

    Science.gov (United States)

    Makowski, Matthew S; Bryan, Isaac; Sitar, Zlatko; Arellano, Consuelo; Xie, Jinqiao; Collazo, Ramon; Ivanisevic, Albena

    2013-07-01

    A label-free kinase detection system was fabricated by the adsorption of gold nanoparticles functionalized with kinase inhibitor onto AlGaN/GaN high electron mobility transistors (HEMTs). The HEMTs were operated near threshold voltage due to the greatest sensitivity in this operational region. The Au NP/HEMT biosensor system electrically detected 1 pM SRC kinase in ionic solutions. These results are pertinent to drug development applications associated with kinase sensing.

  16. Induced base transistor fabricated by molecular beam epitaxy

    Science.gov (United States)

    Chang, C.-Y.; Liu, W. C.; Jame, M. S.; Wang, Y. H.; Luryi, S.

    1986-09-01

    A novel three-terminal hot-electron device, the induced base transistor (IBT), has been fabricated by molecular beam epitaxy. Two-dimensional electron gas induced by the applied collector field in an undoped GaAs quantum well is used as the base of the IBT. The common-base current gain alpha has been achieved as high as 0.96 under a collector bias of 2.5 V and an emitter current of 3 mA.

  17. Micro-irradiation experiments in MOS transistors using synchrotron radiation

    International Nuclear Information System (INIS)

    Spatially-resolved total-dose degradation has been performed in MOS transistors by focusing x-ray synchrotron radiation on the gate electrode with micrometer resolution. The influence of the resulting permanent degradation on device electrical properties has been analyzed using current-voltage and charge pumping measurements, in concert with optical characterization (hot-carrier luminescence) and one-dimensional device simulation. (authors)

  18. Biomolecular detection using a metal semiconductor field effect transistor

    Science.gov (United States)

    Estephan, Elias; Saab, Marie-Belle; Buzatu, Petre; Aulombard, Roger; Cuisinier, Frédéric J. G.; Gergely, Csilla; Cloitre, Thierry

    2010-04-01

    In this work, our attention was drawn towards developing affinity-based electrical biosensors, using a MESFET (Metal Semiconductor Field Effect Transistor). Semiconductor (SC) surfaces must be prepared before the incubations with biomolecules. The peptides route was adapted to exceed and bypass the limits revealed by other types of surface modification due to the unwanted unspecific interactions. As these peptides reveal specific recognition of materials, then controlled functionalization can be achieved. Peptides were produced by phage display technology using a library of M13 bacteriophage. After several rounds of bio-panning, the phages presenting affinities for GaAs SC were isolated; the DNA of these specific phages were sequenced, and the peptide with the highest affinity was synthesized and biotinylated. To explore the possibility of electrical detection, the MESFET fabricated with the GaAs SC were used to detect the streptavidin via the biotinylated peptide in the presence of the bovine Serum Albumin. After each surface modification step, the IDS (current between the drain and the source) of the transistor was measured and a decrease in the intensity was detected. Furthermore, fluorescent microscopy was used in order to prove the specificity of this peptide and the specific localisation of biomolecules. In conclusion, the feasibility of producing an electrical biosensor using a MESFET has been demonstrated. Controlled placement, specific localization and detection of biomolecules on a MESFET transistor were achieved without covering the drain and the source. This method of functionalization and detection can be of great utility for biosensing application opening a new way for developing bioFETs (Biomolecular Field-Effect Transistor).

  19. Intrinsic graphene field effect transistor on amorphous carbon films

    OpenAIRE

    Tinchev, Savcho

    2013-01-01

    Fabrication of graphene field effect transistor is described which uses an intrinsic graphene on the surface of as deposited hydrogenated amorphous carbon films. Ambipolar characteristic has been demonstrated typical for graphene devices, which changes to unipolar characteristic if the surface graphene was etched in oxygen plasma. Because amorphous carbon films can be growth easily, with unlimited dimensions and no transfer of graphene is necessary, this can open new perspective for graphene ...

  20. Organic Field-effect Transistors Based on Tetrathiafulvalene Derivatives

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Restults Tetrathiafulvalene (TTF) and its derivatives have been extensively investigated in the field of organic conductors and superconductors since 1973. Recently, their application in organic field-effect transistors (OFETs) has attracted considerable attention. So far, on the one hand, the fabrication techniques of the TTF-based FETs have been primarily limited to high vacuum evaporation, which is a relatively expensive process. On the other hand, low FET performances, such as the low on/off ratio...

  1. CURRENT PATH IN AMORPHOUS-SILICON FIELD EFFECT TRANSISTORS

    OpenAIRE

    M. MATSUMURA; Kuno, S.; Uchida, Y.

    1981-01-01

    On-resistance of amorphous-silicon field effect transistors with staggered electrodes was investigated. It was found that dependences of the on-resistance on geometrical parameters were classified into two groups. The origin was attributed to the residual resistance between the n+ electrode and the channel which was formed at the silicon-silicon dioxide interface. The resistance was analyzed by taking space charge effect into account, and we found that it changes in accordance with sample pre...

  2. Doping To Reduce Base Resistances Of Bipolar Transistors

    Science.gov (United States)

    Lin, True-Lon

    1991-01-01

    Modified doping profile proposed to reduce base resistance of bipolar transistors. A p/p+ base-doping profile reduces base resistance without reducing current gain. Proposed low/high base-doping profile realized by such low-temperature deposition techniques as molecular-beam epitaxy, ultra-high-vacuum chemical-vapor deposition, and limited-reaction epitaxy. Produces desired doping profiles without excessive diffusion of dopant.

  3. Organic thin film transistor integration a hybrid approach

    CERN Document Server

    Li, Flora; Wu, Yiliang; Ong, Beng S

    2013-01-01

    Research on organic electronics (or plastic electronics) is driven by the need to create systems that are lightweight, unbreakable, and mechanically flexible. With the remarkable improvement in the performance of organic semiconductor materials during the past few decades, organic electronics appeal to innovative, practical, and broad-impact applications requiring large-area coverage, mechanical flexibility, low-temperature processing, and low cost. Thus, organic electronics appeal to a broad range of electronic devices and products including transistors, diodes, sensors, solar cells, lighting

  4. Liquid crystals for organic thin-film transistors

    OpenAIRE

    Iino, Hiroaki; Usui, Takayuki; Hanna, Jun-ichi

    2015-01-01

    Crystalline thin films of organic semiconductors are a good candidate for field effect transistor (FET) materials in printed electronics. However, there are currently two main problems, which are associated with inhomogeneity and poor thermal durability of these films. Here we report that liquid crystalline materials exhibiting a highly ordered liquid crystal phase of smectic E (SmE) can solve both these problems. We design a SmE liquid crystalline material, 2-decyl-7-phenyl-[1]benzothieno[3,...

  5. Transistor electronics use of semiconductor components in switching operations

    CERN Document Server

    Rumpf, Karl-Heinz

    2014-01-01

    Transistor Electronics: Use of Semiconductor Components in Switching Operations presents the semiconductor components as well as their elementary circuits. This book discusses the scope of application of electronic devices to increase productivity. Organized into eight chapters, this book begins with an overview of the general equation for the representation of integer positive numbers. This text then examines the properties and characteristics of basic electronic components, which relates to an understanding of the operation of semiconductors. Other chapters consider the electronic circuit ar

  6. Modeling of non-uniform heat generation in LDMOS transistors

    Science.gov (United States)

    Roig, J.; Flores, D.; Urresti, J.; Hidalgo, S.; Rebollo, J.

    2005-01-01

    This work is devoted to the heat dissipation analysis in LDMOS transistors operating at high current conditions. Hence, a new expression for the Joule heat generated by electron current is provided to simplify the LDMOS electro-thermal modeling, thus giving physical insight and predicting hot spots. The model is based on the semiconductor physics and the required input data are the device geometrical and technological parameters as well as the applied bias.

  7. Fabrication of SWCNT-Graphene Field-Effect Transistors

    OpenAIRE

    Shuangxi Xie; Niandong Jiao; Steve Tung; Lianqing Liu

    2015-01-01

    Graphene and single-walled carbon nanotube (SWCNT) have been widely studied because of their extraordinary electrical, thermal, mechanical, and optical properties. This paper describes a novel and flexible method to fabricate all-carbon field-effect transistors (FETs). The fabrication process begins with assembling graphene grown by chemical vapor deposition (CVD) on a silicon chip with SiO2 as the dielectric layer and n-doped Si substrate as the gate. Next, an atomic force microscopy (AFM)-b...

  8. A scheme for a topological insulator field effect transistor

    Science.gov (United States)

    Vali, Mehran; Dideban, Daryoosh; Moezi, Negin

    2015-05-01

    We propose a scheme for a topological insulator field effect transistor. The idea is based on the gate voltage control of the Dirac fermions in a ferromagnetic topological insulator channel with perpendicular magnetization connecting to two metallic topological insulator leads. Our theoretical analysis shows that the proposed device displays a switching effect with high on/off current ratio and a negative differential conductance with a good peak to valley ratio.

  9. Measurement of the shot noise in a single electron transistor

    OpenAIRE

    Kafanov, Sergey; Delsing, Per

    2008-01-01

    We have systematically measured the shot noise in a single electron transistor (SET) as a function of bias and gate voltages. By embedding a SET in a resonance circuit we have been able to measure its shot noise at the resonance frequency 464 MHz, where the 1/f noise is negligible. We can extract the Fano factor which varies between 0.5 and 1 depending on the amount of Coulomb blockade in the SET, in very good agreement with the theory.

  10. Wavy channel transistor for area efficient high performance operation

    KAUST Repository

    Fahad, Hossain M.

    2013-04-05

    We report a wavy channel FinFET like transistor where the channel is wavy to increase its width without any area penalty and thereby increasing its drive current. Through simulation and experiments, we show the effectiveness of such device architecture is capable of high performance operation compared to conventional FinFETs with comparatively higher area efficiency and lower chip latency as well as lower power consumption.

  11. Advances in organic field-effect transistors and integrated circuits

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Organic field-effect transistors (OFETs) have received significant research interest because of their promising applications in low cast, lager area, plastic circuits, and tremendous progress has been made in materials, device performance, OFETs based circuits in recent years. In this article we introduce the advances in organic semiconductor materials, OFETs based integrating techniques, and in particular highlight the recent progress. Finally, the prospects and problems of OFETs are discussed.

  12. Advances in organic field-effect transistors and integrated circuits

    Institute of Scientific and Technical Information of China (English)

    WANG Hong; JI ZhuoYu; LIU Ming; SHANG LiWei; LIU Ge; LIU XingHua; LIU Jiang; PENG YingQuan

    2009-01-01

    Organic field-effect transistors (OFETs) have received significant research interest because of their promising applications in low cast, lager area, plastic circuits, and tremendous progress has been made in materials, device performance, OFETs based circuits in recent years.In this article we intro-duce the advances in organic semiconductor materials, OFETs based integrating techniques, and in particular highlight the recent progress.Finally, the prospects and problems of OFETs are discussed.

  13. Single shot measurement of a silicon single electron transistor

    OpenAIRE

    Hasko, D. G.; Ferrus, T.; Morrissey, Q. R.; Burge, S. R.; Freeman, E. J.; French, M. J.; Lam, A; Creswell, L.; Collier, R J; Williams, D.A.; Briggs, G. A. D.

    2008-01-01

    We have fabricated a custom cryogenic Complementary Metal-Oxide-Semiconductor (CMOS) integrated circuit that has a higher measurement bandwidth compared with conventional room temperature electronics. This allowed implementing single shot operations and observe the real-time evolution of the current of a phosphorous-doped silicon single electron transistor that was irradiated with a microwave pulse. Relaxation times up to 90 us are observed, suggesting the presence of well isolated electron e...

  14. First-principles modelling of molecular single-electron transistors

    OpenAIRE

    Stokbro, Kurt

    2010-01-01

    We present a first-principles method for calculating the charging energy of a molecular single-electron transistor operating in the Coulomb blockade regime. The properties of the molecule are modeled using density-functional theory, the environment is described by a continuum model, and the interaction between the molecule and the environment are included through the Poisson equation. The model is used to calculate the charge stability diagrams of a benzene and C$_{60}$ molecular single-elect...

  15. Transistor-based metamaterials with dynamically tunable nonlinear susceptibility

    Science.gov (United States)

    Barrett, John P.; Katko, Alexander R.; Cummer, Steven A.

    2016-08-01

    We present the design, analysis, and experimental demonstration of an electromagnetic metamaterial with a dynamically tunable effective nonlinear susceptibility. Split-ring resonators loaded with transistors are shown theoretically and experimentally to act as metamaterials with a second-order nonlinear susceptibility that can be adjusted through the use of a bias voltage. Measurements confirm that this allows for the design of a nonlinear metamaterial with adjustable mixing efficiency.

  16. High-performance carbon nanotube thin-film transistors on flexible paper substrates

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Na; Yun, Ki Nam; Yu, Hyun-Yong; Lee, Cheol Jin, E-mail: cjlee@korea.ac.kr [School of Electrical Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Shim, Joon Hyung [School of Mechanical Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

    2015-03-09

    Single-walled carbon nanotubes (SWCNTs) are promising materials as active channels for flexible transistors owing to their excellent electrical and mechanical properties. However, flexible SWCNT transistors have never been realized on paper substrates, which are widely used, inexpensive, and recyclable. In this study, we fabricated SWCNT thin-film transistors on photo paper substrates. The devices exhibited a high on/off current ratio of more than 10{sup 6} and a field-effect mobility of approximately 3 cm{sup 2}/V·s. The proof-of-concept demonstration indicates that SWCNT transistors on flexible paper substrates could be applied as low-cost and recyclable flexible electronics.

  17. Sub-THz photonic frequency conversion using optoelectronic transistors for future fully coherent access network systems

    Science.gov (United States)

    Otsuji, Taiichi; Sugawara, Kenta; Tamamushi, Gen; Dobroiu, Adrian; Suemitsu, Tetsuya; Ryzhii, Victor; Iwatsuki, Katsumi; Kuwano, Shigeru; Kani, Jun-ichi; Terada, Jun

    2016-02-01

    This paper reviews advances in sub-THz photonic frequency conversion using optoelectronic transistors for future fully coherent access network systems. Graphene-channel field effect transistors (G-FETs) and InP-based high electron mobility transistors (inP-HEMT) are experimentally examined as photonic frequency converters. Optoelectronic properties and three-terminal functionalities of the G-FETs and InP-HEMTs are exploited to perform single-chip photonic double-mixing operation over the 120 GHz wireless communication band. A single transistor can photomix the optical subcarriers to generate LO and mix down the RF data on the sub-THz carrier to the IF band.

  18. Electrically controlled spin-transistor operation in a helical magnetic field

    Science.gov (United States)

    Wójcik, P.; Adamowski, J.

    2016-03-01

    A proposal of an electrically controlled spin transistor in a helical magnetic field is presented. In the proposed device, the transistor action is driven by the Landau-Zener transitions that lead to a backscattering of spin polarized electrons and switching the transistor into the high-resistance state (off state). The on/off state of the transistor can be controlled by the all-electric means using Rashba spin-orbit coupling that can be tuned by the voltages applied to the side electrodes.

  19. Terahertz detection of magnetic field-driven topological phase transition in HgTe-based transistors

    Energy Technology Data Exchange (ETDEWEB)

    Kadykov, A. M. [Laboratoire Charles Coulomb (L2C), UMR CNRS 5221, Universite Montpellier, 34095 Montpellier (France); Institute for Physics of Microstructures, Russian Academy of Sciences, GSP-105, Nizhny Novgorod 603950 (Russian Federation); Teppe, F., E-mail: frederic.teppe@univ-montp2.fr; Consejo, C.; Ruffenach, S.; Marcinkiewicz, M.; Desrat, W.; Dyakonova, N.; Knap, W. [Laboratoire Charles Coulomb (L2C), UMR CNRS 5221, Universite Montpellier, 34095 Montpellier (France); Viti, L.; Vitiello, M. S. [NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa (Italy); Krishtopenko, S. S.; Morozov, S. V.; Gavrilenko, V. I. [Institute for Physics of Microstructures, Russian Academy of Sciences, GSP-105, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, 23 Prospekt Gagarina, 603950 Nizhny Novgorod (Russian Federation); Mikhailov, N. N.; Dvoretsky, S. A. [Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, pr. Akademika Lavrent' eva 13, Novosibirsk 630090 (Russian Federation)

    2015-10-12

    We report on terahertz photoconductivity under magnetic field up to 16 T of field effect transistor based on HgTe quantum well (QW) with an inverted band structure. We observe pronounced cyclotron resonance and Shubnikov-de Haas-like oscillations, indicating a high mobility electron gas in the transistor channel. We discover that nonlinearity of the transistor channel allows for observation of characteristic features in photoconductivity at critical magnetic field corresponding to the phase transition between topological quantum spin Hall and trivial quantum Hall states in HgTe QW. Our results pave the way towards terahertz topological field effect transistors.

  20. Neutron Radiation Effect On 2N2222 And NTE 123 NPN Silicon Bipolar Junction Transistors

    Science.gov (United States)

    Oo, Myo Min; Rashid, N. K. A. Md; Karim, J. Abdul; Zin, M. R. Mohamed; Hasbullah, N. F.

    2013-12-01

    This paper examines neutron radiation with PTS (Pneumatic Transfer System) effect on silicon NPN bipolar junction transistors (2N2222 and NTE 123) and analysis of the transistors in terms of electrical characterization such as current gain after neutron radiation. The key parameters are measured with Keithley 4200SCS. Experiment results show that the current gain degradation of the transistors is very sensitive to neutron radiation. The neutron radiation can cause displacement damage in the bulk layer of the transistor structure. The current degradation is believed to be governed by increasing recombination current between the base and emitter depletion region.

  1. Development and fabrication of improved power transistor switches. [fabrication and manufacturing of semiconductor devices

    Science.gov (United States)

    Hower, P. L.; Chu, C. K.

    1976-01-01

    A new class of high-voltage power transistors has been achieved by adapting present interdigitated thyristor processing techniques to the fabrication of NPN Si transistors. Present devices are 2.3 cm in diameter. The electrical performance obtained is consistent with the predictions of an optimum design theory specifically developed for power switching transistors. The forward safe operating area of the experimental transistors shows a significant improvement over commercially available devices. The report describes device design, wafer processing, and various measurements which include dc characteristics, forward and reverse second breakdown limits, and switching times.

  2. Field-effect transistor chemical sensors of single nanoribbon of copper phthalocyanine

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Copper phthalocyanine (CuPc) nanoribbon field-effect transistors were implemented as chemical sensors. They showed fast response and high reversibility in the detection of the tetrahydrofuran atmosphere at room temperature. The drain current of the field-effect transistor sensor decreased from 6.7 to 0.2 nA when the transistor was measured under the tetrahydrofuran atmosphere. The sensor was self-refreshable in a few minutes. These results demonstrate that the organic single crystalline nanoribbon transistors could effectively act as chemical sensors.

  3. Bipolar junction transistor models for circuit simulation of cosmic-ray-induced soft errors

    Science.gov (United States)

    Benumof, R.; Zoutendyk, J.

    1984-01-01

    This paper examines bipolar junction transistor models suitable for calculating the effects of large excursions of some of the variables determining the operation of a transistor. Both the Ebers-Moll and Gummel-Poon models are studied, and the junction and diffusion capacitances are evaluated on the basis of the latter model. The most interesting result of this analysis is that a bipolar junction transistor when struck by a cosmic particle may cause a single event upset in an electronic circuit if the transistor is operated at a low forward base-emitter bias.

  4. Electrically controlled spin-transistor operation in a helical magnetic field

    International Nuclear Information System (INIS)

    A proposal of an electrically controlled spin transistor in a helical magnetic field is presented. In the proposed device, the transistor action is driven by the Landau–Zener transitions that lead to a backscattering of spin polarized electrons and switching the transistor into the high-resistance state (off state). The on/off state of the transistor can be controlled by the all-electric means using Rashba spin–orbit coupling that can be tuned by the voltages applied to the side electrodes. (paper)

  5. Terahertz detection of magnetic field-driven topological phase transition in HgTe-based transistors

    International Nuclear Information System (INIS)

    We report on terahertz photoconductivity under magnetic field up to 16 T of field effect transistor based on HgTe quantum well (QW) with an inverted band structure. We observe pronounced cyclotron resonance and Shubnikov-de Haas-like oscillations, indicating a high mobility electron gas in the transistor channel. We discover that nonlinearity of the transistor channel allows for observation of characteristic features in photoconductivity at critical magnetic field corresponding to the phase transition between topological quantum spin Hall and trivial quantum Hall states in HgTe QW. Our results pave the way towards terahertz topological field effect transistors

  6. Neutron Radiation Effect On 2N2222 And NTE 123 NPN Silicon Bipolar Junction Transistors

    International Nuclear Information System (INIS)

    This paper examines neutron radiation with PTS (Pneumatic Transfer System) effect on silicon NPN bipolar junction transistors (2N2222 and NTE 123) and analysis of the transistors in terms of electrical characterization such as current gain after neutron radiation. The key parameters are measured with Keithley 4200SCS. Experiment results show that the current gain degradation of the transistors is very sensitive to neutron radiation. The neutron radiation can cause displacement damage in the bulk layer of the transistor structure. The current degradation is believed to be governed by increasing recombination current between the base and emitter depletion region

  7. Ferroelectric Field-Effect Transistor Differential Amplifier Circuit Analysis

    Science.gov (United States)

    Phillips, Thomas A.; MacLeod, Todd C.; Ho, Fat D.

    2008-01-01

    There has been considerable research investigating the Ferroelectric Field-Effect Transistor (FeFET) in memory circuits. However, very little research has been performed in applying the FeFET to analog circuits. This paper investigates the use of FeFETs in a common analog circuit, the differential amplifier. The two input Metal-Oxide-Semiconductor (MOS) transistors in a general MOS differential amplifier circuit are replaced with FeFETs. Resistors are used in place of the other three MOS transistors. The FeFET model used in the analysis has been previously reported and was based on experimental device data. Because of the FeFET hysteresis, the FeFET differential amplifier has four different operating modes depending on whether the FeFETs are positively or negatively polarized. The FeFET differential amplifier operation in the different modes was analyzed by calculating the amplifier voltage transfer and gain characteristics shown in figures 2 through 5. Comparisons were made between the FeFET differential amplifier and the standard MOS differential amplifier. Possible applications and benefits of the FeFET differential amplifier are discussed.

  8. High-Efficiency Harmonically Terminated Diode and Transistor Rectifiers

    Energy Technology Data Exchange (ETDEWEB)

    Roberg, M; Reveyrand, T; Ramos, I; Falkenstein, EA; Popovic, Z

    2012-12-01

    This paper presents a theoretical analysis of harmonically terminated high-efficiency power rectifiers and experimental validation on a class-C single Schottky-diode rectifier and a class-F-1 GaN transistor rectifier. The theory is based on a Fourier analysis of current and voltage waveforms, which arise across the rectifying element when different harmonic terminations are presented at its terminals. An analogy to harmonically terminated power amplifier (PA) theory is discussed. From the analysis, one can obtain an optimal value for the dc load given the RF circuit design. An upper limit on rectifier efficiency is derived for each case as a function of the device on-resistance. Measured results from fundamental frequency source-pull measurement of a Schottky diode rectifier with short-circuit terminations at the second and third harmonics are presented. A maximal device rectification efficiency of 72.8% at 2.45 GHz matches the theoretical prediction. A 2.14-GHz GaN HEMT rectifier is designed based on a class-F-1 PA. The gate of the transistor is terminated in an optimal impedance for self-synchronous rectification. Measurements of conversion efficiency and output dc voltage for varying gate RF impedance, dc load, and gate bias are shown with varying input RF power at the drain. The rectifier demonstrates an efficiency of 85% for a 10-W input RF power at the transistor drain with a dc voltage of 30 V across a 98-Omega resistor.

  9. Organic field-effect transistors using single crystals

    Directory of Open Access Journals (Sweden)

    Tatsuo Hasegawa and Jun Takeya

    2009-01-01

    Full Text Available Organic field-effect transistors using small-molecule organic single crystals are developed to investigate fundamental aspects of organic thin-film transistors that have been widely studied for possible future markets for 'plastic electronics'. In reviewing the physics and chemistry of single-crystal organic field-effect transistors (SC-OFETs, the nature of intrinsic charge dynamics is elucidated for the carriers induced at the single crystal surfaces of molecular semiconductors. Materials for SC-OFETs are first reviewed with descriptions of the fabrication methods and the field-effect characteristics. In particular, a benchmark carrier mobility of 20–40 cm2 Vs−1, achieved with thin platelets of rubrene single crystals, demonstrates the significance of the SC-OFETs and clarifies material limitations for organic devices. In the latter part of this review, we discuss the physics of microscopic charge transport by using SC-OFETs at metal/semiconductor contacts and along semiconductor/insulator interfaces. Most importantly, Hall effect and electron spin resonance (ESR measurements reveal that interface charge transport in molecular semiconductors is properly described in terms of band transport and localization by charge traps.

  10. Organic field-effect transistors using single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Tatsuo [Photonics Research Institute (PRI), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8562 (Japan); Takeya, Jun, E-mail: t-hasegawa@aist.go.j, E-mail: takeya@chem.sci.osaka-u.ac.j [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043 (Japan)

    2009-04-15

    Organic field-effect transistors using small-molecule organic single crystals are developed to investigate fundamental aspects of organic thin-film transistors that have been widely studied for possible future markets for 'plastic electronics'. In reviewing the physics and chemistry of single-crystal organic field-effect transistors (SC-OFETs), the nature of intrinsic charge dynamics is elucidated for the carriers induced at the single crystal surfaces of molecular semiconductors. Materials for SC-OFETs are first reviewed with descriptions of the fabrication methods and the field-effect characteristics. In particular, a benchmark carrier mobility of 20-40 cm{sup 2} Vs{sup -1}, achieved with thin platelets of rubrene single crystals, demonstrates the significance of the SC-OFETs and clarifies material limitations for organic devices. In the latter part of this review, we discuss the physics of microscopic charge transport by using SC-OFETs at metal/semiconductor contacts and along semiconductor/insulator interfaces. Most importantly, Hall effect and electron spin resonance (ESR) measurements reveal that interface charge transport in molecular semiconductors is properly described in terms of band transport and localization by charge traps. (topical review)

  11. Sidewall spacer optimization for steep switching junctionless transistors

    Science.gov (United States)

    Gupta, Manish; Kranti, Abhinav

    2016-06-01

    In this work, we analyze the impact of a high permittivity (high-κ) sidewall spacer and gate dielectric on the occurrence of sub-60 mV/decade subthreshold swing (S-swing) in symmetrical junctionless (JL) double gate (DG) transistors. It is shown that steep S-swing values (≤10 mV/decade) can be achieved in JL devices with a combination of a high permittivity (high-κ) gate dielectric and a narrow low permittivity (low-κ) sidewall spacer. Implementation of a wider high-κ spacer will diminish the degree of impact ionization by the influence of the fringing component of the gate electric field, and will not be useful for steep off-to-on current transition. A wider spacer with low-κ and a narrow spacer with high-κ permittivity will be useful to limit the latching effect that can occur at lower temperatures (250 K). For high temperature operation, the decrease in the impact ionization rate can be compensated by designing a JL transistor with a thicker silicon film. The work demonstrates opportunities to enhance impact ionization at sub bandgap voltages, and proposes optimal guidelines for selecting a sidewall spacer to facilitate steep switching in JL transistors.

  12. Design Optimization of Transistors Used for Neural Recording

    Directory of Open Access Journals (Sweden)

    Eric Basham

    2012-01-01

    Full Text Available Neurons cultured directly over open-gate field-effect transistors result in a hybrid device, the neuron-FET. Neuron-FET amplifier circuits reported in the literature employ the neuron-FET transducer as a current-mode device in conjunction with a transimpedance amplifier. In this configuration, the transducer does not provide any signal gain, and characterization of the transducer out of the amplification circuit is required. Furthermore, the circuit requires a complex biasing scheme that must be retuned to compensate for drift. Here we present an alternative strategy based on the gm/Id design approach to optimize a single-stage common-source amplifier design. The gm/Id design approach facilitates in circuit characterization of the neuron-FET and provides insight into approaches to improving the transistor process design for application as a neuron-FET transducer. Simulation data for a test case demonstrates optimization of the transistor design and significant increase in gain over a current mode implementation.

  13. Top gated graphene transistors with different gate insulators

    Energy Technology Data Exchange (ETDEWEB)

    Pezoldt, Joerg; Hanisch, Antonia [FG Festkoerperelektronik, Institut fuer Mikro- und Nanotechnologien, TU Ilmenau, Postfach 100565, 98684 Ilmenau (Germany); Hummel, Christian; Schwierz, Frank [FG Nanotechnologie, Institut fuer Mikro- und Nanotechnologien, TU Ilmenau, Postfach 100565, 98684 Ilmenau (Germany); Hotovy, Ivan; Kadlecikova, Magdalena [Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Ilkovicova 3, Bratislava 812 19 (Slovakia)

    2010-02-15

    Top gated graphene field effect transistors with AlN and Si{sub 3}N{sub 4} gate insulator materials were fabricated by plasma assisted deposition. Transistors with an AlN top gate insulator showed a reduced mobility and channel carrier density, whereas for the transistors with Si{sub 3}N{sub 4} dielectric an increase of the mobility and a decrease of the channel carrier density was observed. The reduced carrier density can be explained by bond formation between the insulator and the graphene sheets. The different behaviour of the carrier mobility is due to defect passivation by H{sub 2} in case of Si{sub 3}N{sub 4} and defect formation in the graphene channel for the AlN gate insulator. A reduced transconductance in top gate device configurations compared to the back gate configurations was observed, which can be caused by the Klein paradox or differences in the trap densities in the top gate insulators. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Irradiation of graphene field effect transistors with highly charged ions

    Science.gov (United States)

    Ernst, P.; Kozubek, R.; Madauß, L.; Sonntag, J.; Lorke, A.; Schleberger, M.

    2016-09-01

    In this work, graphene field-effect transistors are used to detect defects due to irradiation with slow, highly charged ions. In order to avoid contamination effects, a dedicated ultra-high vacuum set up has been designed and installed for the in situ cleaning and electrical characterization of graphene field-effect transistors during irradiation. To investigate the electrical and structural modifications of irradiated graphene field-effect transistors, their transfer characteristics as well as the corresponding Raman spectra are analyzed as a function of ion fluence for two different charge states. The irradiation experiments show a decreasing mobility with increasing fluences. The mobility reduction scales with the potential energy of the ions. In comparison to Raman spectroscopy, the transport properties of graphene show an extremely high sensitivity with respect to ion irradiation: a significant drop of the mobility is observed already at fluences below 15 ions/μm2, which is more than one order of magnitude lower than what is required for Raman spectroscopy.

  15. Infrared light gated MoS₂ field effect transistor.

    Science.gov (United States)

    Fang, Huajing; Lin, Ziyuan; Wang, Xinsheng; Tang, Chun-Yin; Chen, Yan; Zhang, Fan; Chai, Yang; Li, Qiang; Yan, Qingfeng; Chan, H L W; Dai, Ji-Yan

    2015-12-14

    Molybdenum disulfide (MoS₂) as a promising 2D material has attracted extensive attentions due to its unique physical, optical and electrical properties. In this work, we demonstrate an infrared (IR) light gated MoS₂ transistor through a device composed of MoS₂ monolayer and a ferroelectric single crystal Pb(Mg(1/3)Nb(2/3))O₃-PbTiO₃ (PMN-PT). With a monolayer MoS₂ onto the top surface of (111) PMN-PT crystal, the drain current of MoS₂ channel can be modulated with infrared illumination and this modulation process is reversible. Thus, the transistor can work as a new kind of IR photodetector with a high IR responsivity of 114%/Wcm⁻². The IR response of MoS₂ transistor is attributed to the polarization change of PMN-PT single crystal induced by the pyroelectric effect which results in a field effect. Our result promises the application of MoS₂ 2D material in infrared optoelectronic devices. Combining with the intrinsic photocurrent feature of MoS₂ in the visible range, the MoS₂ on ferroelectric single crystal may be sensitive to a broadband wavelength of light. PMID:26698982

  16. Organic field-effect transistors using single crystals

    International Nuclear Information System (INIS)

    Organic field-effect transistors using small-molecule organic single crystals are developed to investigate fundamental aspects of organic thin-film transistors that have been widely studied for possible future markets for 'plastic electronics'. In reviewing the physics and chemistry of single-crystal organic field-effect transistors (SC-OFETs), the nature of intrinsic charge dynamics is elucidated for the carriers induced at the single crystal surfaces of molecular semiconductors. Materials for SC-OFETs are first reviewed with descriptions of the fabrication methods and the field-effect characteristics. In particular, a benchmark carrier mobility of 20-40 cm2 Vs-1, achieved with thin platelets of rubrene single crystals, demonstrates the significance of the SC-OFETs and clarifies material limitations for organic devices. In the latter part of this review, we discuss the physics of microscopic charge transport by using SC-OFETs at metal/semiconductor contacts and along semiconductor/insulator interfaces. Most importantly, Hall effect and electron spin resonance (ESR) measurements reveal that interface charge transport in molecular semiconductors is properly described in terms of band transport and localization by charge traps. (topical review)

  17. Capacitance-modulated transistor detects odorant binding protein chiral interactions

    Science.gov (United States)

    Mulla, Mohammad Yusuf; Tuccori, Elena; Magliulo, Maria; Lattanzi, Gianluca; Palazzo, Gerardo; Persaud, Krishna; Torsi, Luisa

    2015-01-01

    Peripheral events in olfaction involve odorant binding proteins (OBPs) whose role in the recognition of different volatile chemicals is yet unclear. Here we report on the sensitive and quantitative measurement of the weak interactions associated with neutral enantiomers differentially binding to OBPs immobilized through a self-assembled monolayer to the gate of an organic bio-electronic transistor. The transduction is remarkably sensitive as the transistor output current is governed by the small capacitance of the protein layer undergoing minute changes as the ligand-protein complex is formed. Accurate determination of the free-energy balances and of the capacitance changes associated with the binding process allows derivation of the free-energy components as well as of the occurrence of conformational events associated with OBP ligand binding. Capacitance-modulated transistors open a new pathway for the study of ultra-weak molecular interactions in surface-bound protein-ligand complexes through an approach that combines bio-chemical and electronic thermodynamic parameters.

  18. Ballistic modeling of InAs nanowire transistors

    Science.gov (United States)

    Jansson, Kristofer; Lind, Erik; Wernersson, Lars-Erik

    2016-01-01

    In this work, the intrinsic performance of InAs nanowire transistors is evaluated in the ballistic limit. A self-consistent Schrödinger-Poisson solver is utilized in the cylindrical geometry, while accounting for conduction band non-parabolicity. The transistor characteristics are derived from simulations of ballistic transport within the nanowire. Using this approach, the performance is calculated for a continuous range of nanowire diameters and the transport properties are mapped. A transconductance exceeding 4S /mm is predicted at a gate overdrive of 0.5V and it is shown that the performance is improved with scaling. Furthermore, the influence from including self-consistency and non-parabolicity in the band structure simulations is quantified. It is demonstrated that the effective mass approximation underestimates the transistor performance due to the highly non-parabolic conduction band in InAs. Neglecting self-consistency severely overestimates the device performance, especially for thick nanowires. The error introduced by both of these approximations gets increasingly worse under high bias conditions.

  19. TOPICAL REVIEW: Organic field-effect transistors using single crystals

    Science.gov (United States)

    Hasegawa, Tatsuo; Takeya, Jun

    2009-04-01

    Organic field-effect transistors using small-molecule organic single crystals are developed to investigate fundamental aspects of organic thin-film transistors that have been widely studied for possible future markets for 'plastic electronics'. In reviewing the physics and chemistry of single-crystal organic field-effect transistors (SC-OFETs), the nature of intrinsic charge dynamics is elucidated for the carriers induced at the single crystal surfaces of molecular semiconductors. Materials for SC-OFETs are first reviewed with descriptions of the fabrication methods and the field-effect characteristics. In particular, a benchmark carrier mobility of 20-40 cm2 Vs-1, achieved with thin platelets of rubrene single crystals, demonstrates the significance of the SC-OFETs and clarifies material limitations for organic devices. In the latter part of this review, we discuss the physics of microscopic charge transport by using SC-OFETs at metal/semiconductor contacts and along semiconductor/insulator interfaces. Most importantly, Hall effect and electron spin resonance (ESR) measurements reveal that interface charge transport in molecular semiconductors is properly described in terms of band transport and localization by charge traps.

  20. Single-layer MoS2 transistors.

    Science.gov (United States)

    Radisavljevic, B; Radenovic, A; Brivio, J; Giacometti, V; Kis, A

    2011-03-01

    Two-dimensional materials are attractive for use in next-generation nanoelectronic devices because, compared to one-dimensional materials, it is relatively easy to fabricate complex structures from them. The most widely studied two-dimensional material is graphene, both because of its rich physics and its high mobility. However, pristine graphene does not have a bandgap, a property that is essential for many applications, including transistors. Engineering a graphene bandgap increases fabrication complexity and either reduces mobilities to the level of strained silicon films or requires high voltages. Although single layers of MoS(2) have a large intrinsic bandgap of 1.8 eV (ref. 16), previously reported mobilities in the 0.5-3 cm(2) V(-1) s(-1) range are too low for practical devices. Here, we use a halfnium oxide gate dielectric to demonstrate a room-temperature single-layer MoS(2) mobility of at least 200 cm(2) V(-1) s(-1), similar to that of graphene nanoribbons, and demonstrate transistors with room-temperature current on/off ratios of 1 × 10(8) and ultralow standby power dissipation. Because monolayer MoS(2) has a direct bandgap, it can be used to construct interband tunnel FETs, which offer lower power consumption than classical transistors. Monolayer MoS(2) could also complement graphene in applications that require thin transparent semiconductors, such as optoelectronics and energy harvesting. PMID:21278752

  1. Atmospheric pressure chemical vapour deposition of vanadium arsenide thin films via the reaction of VCl4 or VOCl3 with tBuAsH2

    International Nuclear Information System (INIS)

    Thin films of vanadium arsenide were deposited via the dual-source atmospheric pressure chemical vapour deposition reactions of VCl4 or VOCl3 with tBuAsH2. Using the vanadium precursor VCl4, films were deposited at substrate temperatures of 550–600 °C, which were black-gold in appearance and were found to be metal-rich with high levels of chlorine incorporation. The use of VOCl3 as the vanadium source resulted in films being deposited between 450 and 600 °C and, unlike when using VCl4, were silver in appearance. The films deposited using VOCl3 demonstrated vanadium to arsenic ratios close to 1:1, and negligible chlorine incorporation. Films deposited using either vanadium precursor were identified as VAs using powder X-ray diffraction and possessed borderline metallic/semiconductor resistivities. - Highlights: • Formation of VAs films via atmospheric pressure chemical vapour deposition. • Films formed using VCl4 or VOCl3 and tBuAsH2. • Powder X-ray diffraction showed that crystalline VAs films were deposited. • Films from VOCl3 had a V:As ratio close to 1 with negligible Cl incorporation. • Films were silver and possessed borderline metallic/semiconductor resistivities

  2. Note: All solid-state high repetitive sub-nanosecond risetime pulse generator based on bulk gallium arsenide avalanche semiconductor switches

    Science.gov (United States)

    Hu, Long; Su, Jiancang; Ding, Zhenjie; Hao, Qingsong; Fan, Yajun; Liu, Chunliang

    2016-08-01

    An all solid-state high repetitive sub-nanosecond risetime pulse generator featuring low-energy-triggered bulk gallium arsenide (GaAs) avalanche semiconductor switches and a step-type transmission line is presented. The step-type transmission line with two stages is charged to a potential of 5.0 kV also biasing at the switches. The bulk GaAs avalanche semiconductor switch closes within sub-nanosecond range when illuminated with approximately 87 nJ of laser energy at 905 nm in a single pulse. An asymmetric dipolar pulse with peak-to-peak amplitude of 9.6 kV and risetime of 0.65 ns is produced on a resistive load of 50 Ω. A technique that allows for repetition-rate multiplication of pulse trains experimentally demonstrated that the parallel-connected bulk GaAs avalanche semiconductor switches are triggered in sequence. The highest repetition rate is decided by recovery time of the bulk GaAs avalanche semiconductor switch, and the operating result of 100 kHz of the generator is discussed.

  3. Velocity Saturation of Hot Carriers in Two-Dimensional Transistors

    Science.gov (United States)

    Bird, Jonathan

    Two-dimensional (2D) materials, including graphene and transition-metal dichalcogenides, have emerged in recent years as possible ``channel-replacement'' materials for use in future generations of post-CMOS devices. Realizing the full potential of these materials requires strategies to maximize their current-carrying capacity, while minimizing Joule losses to its environment. A major source of dissipation for hot carriers in any semiconductor is spontaneous optical-phonon emission, resulting in saturation of the drift velocity. In this presentation, I discuss the results of studies of velocity saturation in both graphene and molybdenum-disulphide transistors, emphasizing how this phenomenon impacts resulting transistor operation. While in graphene the large intrinsic optical-phonon energies promise high saturation velocities, experiments to date have revealed a significant degradation of the drift velocity that arises from the loss of energy from hot carriers to the underlying substrate. I discuss here how this problem can be overcome by implementing a strategy of nanosecond electrical pulsing [H. Ramamoorthy et al., Nano Lett., under review], as a means to drive graphene's hot carriers much faster than substrate heating can occur. In this way we achieve saturation velocities that approach the Fermi velocity near the Dirac point, and which exceed those reported for suspended graphene and for devices fabricated on boron nitride substrates. Corresponding current densities reach those found in carbon nanotubes, and in graphene-on-diamond transistors. In this sense we are able to ``free'' graphene from the influence of its substrate, revealing a pathway to achieve the superior electrical performance promised by this material. Velocity saturation is also found to be important for the operation of monolayer molybdenum-disulphide transistors, where it limits the drain current observed in saturation [G. He et al., Nano Lett. 15, 5052 (2015)]. The implications of these

  4. A 0.5-V Six-Transistor Static Random Access Memory with Ferroelectric-Gate Field Effect Transistors

    Science.gov (United States)

    Tanakamaru, Shuhei; Hatanaka, Teruyoshi; Yajima, Ryoji; Miyaji, Kousuke; Takahashi, Mitsue; Sakai, Shigeki; Takeuchi, Ken

    2010-12-01

    A 0.5 V six-transistor static random access memory (6T-SRAM) with ferroelectric-gate field-effect-transistors (Fe-FETs) is proposed and experimentally demonstrated for the first time. During the read and the hold, the threshold voltage (VTH) of Fe-FETs automatically changes to increase the static noise margin (SNM) by 60%. During the stand-by, the VTH of the proposed SRAM cell increases to decrease the leakage current by 42%. In case of the read, the VTH of the read transistor decreases and increases the cell read current to achieve the fast read. During the write, the VTH of the SRAM cell dynamically changes and assist the cell data to flip, realizing a write assist function. The enlarged SNM realizes the VDD reduction by 0.11 V, which decreases the active power by 32%. The proposed SRAM layout is the same as the conventional 6T-SRAM and there is no area penalty.

  5. The dual role of multiple-transistor charge sharing collection in single-event transients

    Institute of Scientific and Technical Information of China (English)

    Guo Yang; Chen Jian-Jun; He Yi-Bai; Liang Bin; Liu Bi-Wei

    2013-01-01

    As technologies scale down in size,multiple-transistors being affected by a single ion has become a universal phenomenon,and some new effects are present in single event transients (SETs) due to the charge sharing collection of the adjacent multiple-transistors.In this paper,not only the off-state p-channel metal-oxide semiconductor field-effect transistor (PMOS FET),but also the on-state PMOS is struck by a heavy-ion in the two-transistor inverter chain,due to the charge sharing collection and the electrical interaction.The SET induced by striking the off-state PMOS is efficiently mitigated by the pulse quenching effect,but the SET induced by striking the on-state PMOS becomes dominant.It is indicated in this study that in the advanced technologies,the SET will no longer just be induced by an ion striking the off-state transistor,and the SET sensitive region will no longer just surround the off-state transistor either,as it is in the older technologies.We also discuss this issue in a three-transistor inverter in depth,and the study illustrates that the three-transistor inverter is still a better replacement for spacebome integrated circuit design in advanced technologies.

  6. Controlled n-Type Doping of Carbon Nanotube Transistors by an Organorhodium Dimer.

    Science.gov (United States)

    Geier, Michael L; Moudgil, Karttikay; Barlow, Stephen; Marder, Seth R; Hersam, Mark C

    2016-07-13

    Single-walled carbon nanotube (SWCNT) transistors are among the most developed nanoelectronic devices for high-performance computing applications. While p-type SWCNT transistors are easily achieved through adventitious adsorption of atmospheric oxygen, n-type SWCNT transistors require extrinsic doping schemes. Existing n-type doping strategies for SWCNT transistors suffer from one or more issues including environmental instability, limited carrier concentration modulation, undesirable threshold voltage control, and/or poor morphology. In particular, commonly employed benzyl viologen n-type doping layers possess large thicknesses, which preclude top-gate transistor designs that underlie high-density integrated circuit layouts. To overcome these limitations, we report here the controlled n-type doping of SWCNT thin-film transistors with a solution-processed pentamethylrhodocene dimer. The charge transport properties of organorhodium-treated SWCNT thin films show consistent n-type behavior when characterized in both Hall effect and thin-film transistor geometries. Due to the molecular-scale thickness of the organorhodium adlayer, large-area arrays of top-gated, n-type SWCNT transistors are fabricated with high yield. This work will thus facilitate ongoing efforts to realize high-density SWCNT integrated circuits. PMID:27253896

  7. A method for the measurement of the turn-on condition in MOS transistors

    NARCIS (Netherlands)

    Wallinga, H.

    1971-01-01

    Metal-oxide-silicon (MOS) integrated circuits usually consist of MOS transistors and interconnections. Both, interconnections and MOS transistors are built up of diffused regions in the bulk substrate and conductive strips (metal or polycrystalline silicon) on top of the oxide. For proper electrical

  8. Fast turn-on of an NMOS ESD protection transistor: measurements and simulations

    NARCIS (Netherlands)

    Luchies, J.R.M.; Kort, de C.G.M.; Verweij, J.F.

    1995-01-01

    The transient turn-on of the parasitic bipolar transistor of an NMOS transistor was studied. The voltages appearing at internal nodes of protection and functional circuit after application of 350 ps rise-time pulses have been measured using electro-optic sampling. For very fast transients the trigge

  9. 1/f Noise Characterization in CMOS Transistors in 0.13μm Technology

    DEFF Research Database (Denmark)

    Citakovic, J.; Stenberg, L J; Andreani, Pietro

    2006-01-01

    Low-frequency noise has been studied on a set of n- and p-channel CMOS transistors fabricated in a 0.13μm technology. Noise measurements have been performed on transistors with different gate lengths operating under wide bias conditions, ranging from weak to strong inversion. Noise origin has been...

  10. Electrical Characteristics of Copper Phthalocyanine Thin-Film Transistors with Polyamide-6/Polytetrafluoroethylene Gate Insulator

    Institute of Scientific and Technical Information of China (English)

    YU Shun-Yang; XU Shi-Ai; MA Dong-Ge

    2007-01-01

    Polyamide-6(PA 6)/polytetrafluoroethylene is studied as a potential gate dielectric for flexible organic thin film transistors.The salne method used for the formation of organic semiconductor and gate dielectric films greatly simplifies the fabrication process of devices.The fabricated transistors show good electrical characteristics.Ambipolar behaviour is observed even when the device is operated in air.

  11. Electrothermal Behavior of High-Frequency Silicon-On-Glass Transistors

    NARCIS (Netherlands)

    Nenadovic, N.

    2004-01-01

    In this thesis, research is focused on the investigation of electrothermal effects in high-speed silicon transistors. At high current levels the power dissipation in these devices can lead to heating of both the device itself and the adjacent devices. In advanced transistors these effects are becomi

  12. Dynamics of threshold voltage shifts in organic and amorphous silicon field-effect transistors

    NARCIS (Netherlands)

    Mathijssen, Simon G. J.; Colle, Michael; Gomes, Henrique; Smits, Edsger C. P.; de Boer, Bert; McCulloch, Iain; Bobbert, Peter A.; de Leeuw, Dago M.; Cölle, Michael

    2007-01-01

    The electrical instability of organic field-effect transistors is investigated. We observe that the threshold-voltage shift (see figure) shows a stretched-exponential time dependence under an applied gate bias. The activation energy of 0.6 eV is common for our and all other organic transistors repor

  13. Evaluation of temperature-enhanced gain degradation of verticle npn and lateral pnp bipolar transistors

    Energy Technology Data Exchange (ETDEWEB)

    Witczak, S.C.; Lacoe, R.C. [Aerospace Corp., Los Angeles, CA (United States). Electronics Technology Center; Galloway, K.F. [Vanderbilt Univ., Nashville, TN (United States). Dept. of Electrical and Computer Engineering] [and others

    1997-03-01

    The effect of dose rate on radiation-induced gain degradation is compared for verticle npn and lateral pnp bipolar transistors. High dose rate irradiations at elevated temperatures are more effective at simulating low dose rate degradation in the lateral pnp transistors.

  14. E-Learning System for Design and Construction of Amplifier Using Transistors

    Science.gov (United States)

    Takemura, Atsushi

    2014-01-01

    This paper proposes a novel e-Learning system for the comprehensive understanding of electronic circuits with transistors. The proposed e-Learning system allows users to learn a wide range of topics, encompassing circuit theories, design, construction, and measurement. Given the fact that the amplifiers with transistors are an integral part of…

  15. Graphene-based lateral heterostructure transistors exhibit better intrinsic performance than graphene-based vertical transistors as post-CMOS devices

    Science.gov (United States)

    Logoteta, Demetrio; Fiori, Gianluca; Iannaccone, Giuseppe

    2014-10-01

    We investigate the intrinsic performance of vertical and lateral graphene-based heterostructure field-effect transistors, currently considered the most promising options to exploit graphene properties in post-CMOS electronics. We focus on three recently proposed graphene-based transistors, that in experiments have exhibited large current modulation. Our analysis is based on device simulations including the self-consistent solution of the electrostatic and transport equations within the Non-Equilibrium Green's Function formalism. We show that the lateral heterostructure transistor has the potential to outperform CMOS technology and to meet the requirements of the International Technology Roadmap for Semiconductors for the next generation of semiconductor integrated circuits. On the other hand, we find that vertical heterostructure transistors miss these performance targets by several orders of magnitude, both in terms of switching frequency and delay time, due to large intrinsic capacitances, and unavoidable current/capacitance tradeoffs.

  16. Performance Analysis of Silicon and Germanium Nanowire Transistor using Crystal Orientation and Oxide Thickness

    Directory of Open Access Journals (Sweden)

    P.Theres Mary

    2014-09-01

    Full Text Available Nanowire Transistors have attracted attention due to the probable high performance and excellent controllability of device current. In this paper, we investigate the performance analysis of nanowire transistors made of silicon and germanium materials. The nanowire transistor has a 3D distribution of electron density and electrostatic potential, therefore self-consistent 3D simulations are used. Nanowire (tool is 3D Poisson self-consistent simulator which can study the 3D transport in nanowire transistor considering phonon scattering based on the effective-mass approximation. The output characteristics of the nanowire transistors are studied in detail for both Si and Ge materials for different transport orientation (i.e., 100,110,111 and varying the oxide thickness.

  17. Studying the operation characteristics and structure of vertical channel copper-phthalocyanine organic semiconductor transistor

    Institute of Scientific and Technical Information of China (English)

    ZHU Min; SONG Ming-xin; GUI Tai-long; WANG Xuan; YIN Jing-hua; WANG Dong-xing; ZHAO Hong

    2005-01-01

    The creation of Au/CuPc/Al/CuPc/structure is a perpendicular type electricity found in the channel of organic static induction transistor. In the following we analyze transistor operation characteristics and machine structural relation. The results express that the transistor drives the voltage low and has no-saturation currentvoltage characteristics. Its operation characteristics are dependant on gate bias voltage and the construction of the aluminum electrode.The vertical channel of organic static induction transistor (OSIT) , with structure of Au/CuPc/Al/CuPc/Cu, has been determined. According to the test results, the relation of its operation characteristics and device structure was analyzed. The results show that this transistor has a low driving voltage and unsaturation Ⅰ-Ⅴ characteristics. Its operation characteristics are dependant on gate bias voltage and the structure of the aluminum electrode.

  18. Parametrization of the radiation induced leakage current increase of NMOS transistors

    CERN Document Server

    Backhaus, Malte

    2016-01-01

    The increase of the leakage current of NMOS transistors during exposure to ionizing radiation is known and well studied. Radiation hardness by design techniques have been developed to mitigate this effect and have been successfully used. More recent developments in smaller feature size technologies do not make use of these techniques due to their drawbacks in terms of logic density and requirement of dedicated libraries. During operation the resulting increase of the supply current is a serious challenge and needs to be considered during the system design. A simple parametrization of the leakage current of NMOS transistors as a function of total ionizing dose is presented. The parametrization uses a transistor transfer characteristics of the parasitic transistor along the shallow trench isolation to describe the leakage current of the nominal transistor. Together with a parametrization of the number of positive charges trapped in the silicon dioxide and number of activated interface traps in the silicon to si...

  19. Low-Voltage, Low-Power, Organic Light-Emitting Transistors for Active Matrix Displays

    Science.gov (United States)

    McCarthy, M. A.; Liu, B.; Donoghue, E. P.; Kravchenko, I.; Kim, D. Y.; So, F.; Rinzler, A. G.

    2011-04-01

    Intrinsic nonuniformity in the polycrystalline-silicon backplane transistors of active matrix organic light-emitting diode displays severely limits display size. Organic semiconductors might provide an alternative, but their mobility remains too low to be useful in the conventional thin-film transistor design. Here we demonstrate an organic channel light-emitting transistor operating at low voltage, with low power dissipation, and high aperture ratio, in the three primary colors. The high level of performance is enabled by a single-wall carbon nanotube network source electrode that permits integration of the drive transistor and the light emitter into an efficient single stacked device. The performance demonstrated is comparable to that of polycrystalline-silicon backplane transistor-driven display pixels.

  20. Specifics of Pulsed Arc Welding Power Supply Performance Based On A Transistor Switch

    Science.gov (United States)

    Krampit, N. Yu; Kust, T. S.; Krampit, M. A.

    2016-08-01

    Specifics of designing a pulsed arc welding power supply device are presented in the paper. Electronic components for managing large current was analyzed. Strengths and shortcomings of power supply circuits based on thyristor, bipolar transistor and MOSFET are outlined. As a base unit for pulsed arc welding was chosen MOSFET transistor, which is easy to manage. Measures to protect a transistor are given. As for the transistor control device is a microcontroller Arduino which has a low cost and adequate performance of the work. Bead transfer principle is to change the voltage on the arc in the formation of beads on the wire end. Microcontroller controls transistor when the arc voltage reaches the threshold voltage. Thus there is a separation and transfer of beads without splashing. Control strategies tested on a real device and presented. The error in the operation of the device is less than 25 us, it can be used controlling drop transfer at high frequencies (up to 1300 Hz).

  1. The total dose effects on the 1/f noise of deep submicron CMOS transistors

    International Nuclear Information System (INIS)

    Using 0.18 μm CMOS transistors, the total dose effects on the 1/f noise of deep-submicron CMOS transistors are studied for the first time in mainland China. From the experimental results and the theoretic analysis, we realize that total dose radiation causes a lot of trapped positive charges in STI (shallow trench isolation) SiO2 layers, which induces a current leakage passage, increasing the 1/f noise power of CMOS transistors. In addition, we design some radiation-hardness structures on the CMOS transistors and the experimental results show that, until the total dose achieves 750 krad, the 1/f noise power of the radiation-hardness CMOS transistors remains unchanged, which proves our conclusion. (semiconductor devices)

  2. Electrostatic control of polarity of α-MoTe2 transistors with dual top gates

    Science.gov (United States)

    Nakaharai, Shu; Yamamoto, Mahito; Ueno, Keiji; Lin, Yen-Fu; Li, Song-Lin; Tsukagoshi, Kazuhito

    2015-03-01

    Transition metal dichalcogenides have been expected for future applications in nanoelectronics due to their unique features of the atomically-thin structure. Using semiconducting α-molybdenum ditelluride (α-MoTe2) , we realized field effect transistors (FETs) in which the polarity (n- or p-type) can be electrostatically controlled without impurity doping. The fabricated device had a pair of top gates (aluminum electrode on silicon dioxide) attached in series with a gap length of 100 nm in between. We experimentally performed transistor operations in both n-FET and p-FET modes in a single device by changing the voltage applied to one of the two top gates, which determined the transistor polarity, and sweeping the bias of the other gate. The demonstrated reversibility of the transistor polarity will contribute to the renovated architecture of logic circuits with lower numbers of transistors and hence the lower power consumption than the conventional technology.

  3. Fabrication de transistors monoelectroniques pour la detection de charge

    Science.gov (United States)

    Richard, Jean-Philippe

    Le transistor monoelectro'nique (SET) est un candidat que l'on croyait avoir la capacite de remplacer le transistor des circuits integres actuel (MOSFET). Pour des raisons de faible gain en voltage, d'impedance de sortie elevee et de sensibilite aux fluctuations de charges, il est considere aujourd'hui qu'un hybride tirant profit des deux technologies est plus avantageux. En exploitant sa lacune d'etre sensible aux variations de charge, le SET est davantage utilise dans des applications ou la detection de charge s'avere indispensable, notamment dans les domaines de la bio-detection et de l'informatique quantique. Ce memoire presente une etude du transistor monoelectronique utilise en tant que detecteur de charge. La methode de fabrication est basee sur le procede nanodamascene developpe par Dubuc et al. [11] permettant au transistor monoelectronique de fonctionner a temperature ambiante. La temperature d'operation etant intimement liee a la geometrie du SET, la cle du procede nanodamascene reside dans le polissage chimico-mecanique (CMP) permettant de reduire l'epaisseur des SET jusqu'a des valeurs de quelques nanametres. Dans ce projet de maitrise, nous avons cependant opte pour que le SET soit opere a temperature cryogenique. Une faible temperature d'operation permet le relachement des contraintes de dimensions des dispositifs. En considerant les variations de procedes normales pouvant survenir lors de la fabrication, la temperature d'operation maximale calculee en conception s'etend de 27 K a 90 K, soit une energie de charge de 78 meV a 23 meV. Le gain du detecteur de charge etant dependant de la distance de couplage, les resultats de simulations demontrent que cette distance doit etre de 200 nm pour que la detection de charge soit optimale. Les designs concus sont ensuite fabriques sur substrat d'oxyde de silicium. Les resultats de fabrication de SET temoignent de la robustesse du procede nanodamascene. En effet, les dimensions atteintes experimentalement s

  4. Black Phosphorus Flexible Thin Film Transistors at Gighertz Frequencies.

    Science.gov (United States)

    Zhu, Weinan; Park, Saungeun; Yogeesh, Maruthi N; McNicholas, Kyle M; Bank, Seth R; Akinwande, Deji

    2016-04-13

    Black phosphorus (BP) has attracted rapidly growing attention for high speed and low power nanoelectronics owing to its compelling combination of tunable bandgap (0.3 to 2 eV) and high carrier mobility (up to ∼1000 cm(2)/V·s) at room temperature. In this work, we report the first radio frequency (RF) flexible top-gated (TG) BP thin-film transistors on highly bendable polyimide substrate for GHz nanoelectronic applications. Enhanced p-type charge transport with low-field mobility ∼233 cm(2)/V·s and current density of ∼100 μA/μm at VDS = -2 V were obtained from flexible BP transistor at a channel length L = 0.5 μm. Importantly, with optimized dielectric coating for air-stability during microfabrication, flexible BP RF transistors afforded intrinsic maximum oscillation frequency fMAX ∼ 14.5 GHz and unity current gain cutoff frequency fT ∼ 17.5 GHz at a channel length of 0.5 μm. Notably, the experimental fT achieved here is at least 45% higher than prior results on rigid substrate, which is attributed to the improved air-stability of fabricated BP devices. In addition, the high-frequency performance was investigated through mechanical bending test up to ∼1.5% tensile strain, which is ultimately limited by the inorganic dielectric film rather than the 2D material. Comparison of BP RF devices to other 2D semiconductors clearly indicates that BP offers the highest saturation velocity, an important metric for high-speed and RF flexible nanosystems. PMID:26977902

  5. Simulation of 50-nm Gate Graphene Nanoribbon Transistors

    Directory of Open Access Journals (Sweden)

    Cedric Nanmeni Bondja

    2016-01-01

    Full Text Available An approach to simulate the steady-state and small-signal behavior of GNR MOSFETs (graphene nanoribbon metal-semiconductor-oxide field-effect transistor is presented. GNR material parameters and a method to account for the density of states of one-dimensional systems like GNRs are implemented in a commercial device simulator. This modified tool is used to calculate the current-voltage characteristics as well the cutoff frequency fT and the maximum frequency of oscillation fmax of GNR MOSFETs. Exemplarily, we consider 50-nm gate GNR MOSFETs with N = 7 armchair GNR channels and examine two transistor configurations. The first configuration is a simplified MOSFET structure with a single GNR channel as usually studied by other groups. Furthermore, and for the first time in the literature, we study in detail a transistor structure with multiple parallel GNR channels and interribbon gates. It is shown that the calculated fT of GNR MOSFETs is significantly lower than that of GFETs (FET with gapless large-area graphene channel with comparable gate length due to the mobility degradation in GNRs. On the other hand, GNR MOSFETs show much higher fmax compared to experimental GFETs due the semiconducting nature of the GNR channels and the resulting better saturation of the drain current. Finally, it is shown that the gate control in FETs with multiple parallel GNR channels is improved while the cutoff frequency is degraded compared to single-channel GNR MOSFETs due to parasitic capacitances of the interribbon gates.

  6. Generation System of Concentrator Photovoltaic Based on Gallium Arsenide Cells%基于砷化镓电池的聚光光伏发电系统

    Institute of Scientific and Technical Information of China (English)

    宁铎; 王辉辉; 黄建兵; 李明勇

    2011-01-01

    Solar photovoltaic power generation system for the problem of low utilization, a generation system of concentrator photovoltaic (CPV) based on gallium arsenide (GaAs) cells can be designed. The system consists of concentrating power modules, solar tracking module, inverter module. Fresnel lens concentrator power generation module 400 times by concentrating light in lcm2 GaAs after the battery,the realization of power function; sun-tracking modules and optical sensors from the head to ensure that the basic vertical sunlight through the Fresnel lens; GaAs inverter module converts DC battery AC issued. After testing, the system reached 20. 2% conversion efficiency of solar, inverter part of the realization of the exchange function of the DC variable.%针对光伏发电系统中太阳能利用率低的问题,设计了一种基于砷化镓(GaAs)电池的聚光光伏(CPV)发电系统;该系统由聚光发电模块、太阳跟踪模块和逆变模块组成;聚光发电模块采用菲涅尔透镜400倍聚光以后照射在1Cmz的砷化镓电池上,实现发电功能;太阳跟踪模块由云台和光电传感器组成,保证太阳光基本垂直通过菲涅尔透镜,逆变模块将砷化镓电池发出的直流电转换成交流电;经过测试.该系统太阳能转换效率达到20.2%,逆变部分实现了直流变交流功能.

  7. The Reliability of III-V semiconductor Heterojunction Bipolar Transistors

    OpenAIRE

    M. Borgarino; Plana, R.; Graffeuil, J; Cattani, L; F. Fantini

    2000-01-01

    The Heterojunction Bipolar Transistor (HBT) features some characteristics that make it a very promising device in the telecom field. For these applications, the reliability is a key issue. The aim of the present paper is to summarise the most relevant reliability concerns, from whose the HBT suffers, as the stability of the ohmic contact, the presence of defects, and the stability of the base dopant. Since in the last years the Si/SiGe HBT has emerged as a strong competitor against the III-V ...

  8. Room-temperature single-electron transistors using alkanedithiols

    Energy Technology Data Exchange (ETDEWEB)

    Luo Kang; Chae, D-H; Yao Zhen [Department of Physics, University of Texas at Austin, Austin, TX 78712 (United States); Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, TX 78712 (United States); Texas Materials Institute, University of Texas at Austin, Austin, TX 78712 (United States)

    2007-11-21

    We have fabricated single-electron transistors by alkanedithiol molecular self-assembly. The devices consist of spontaneously formed ultrasmall Au nanoparticles linked by alkanedithiols to nanometer-spaced Au electrodes created by electromigration. The devices reproducibly exhibit addition energies of a few hundred meV, which enables the observation of single-electron tunneling at room temperature. At low temperatures, tunneling through discrete energy levels in the Au nanoparticles is observed, which is accompanied by the excitations of molecular vibrations at large bias voltage.

  9. Intrinsic magnetic refrigeration of a single electron transistor

    Energy Technology Data Exchange (ETDEWEB)

    Ciccarelli, C.; Ferguson, A. J. [Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE (United Kingdom); Campion, R. P.; Gallagher, B. L. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

    2016-02-01

    In this work, we show that aluminium doped with low concentrations of magnetic impurities can be used to fabricate quantum devices with intrinsic cooling capabilities. We fabricate single electron transistors made of aluminium doped with 2% Mn by using a standard multi angle evaporation technique and show that the quantity of metal used to fabricate the devices generates enough cooling power to achieve a drop of 160 mK in the electron temperature at the base temperature of our cryostat (300 mK). The cooling mechanism is based on the magneto-caloric effect from the diluted Mn moments.

  10. Electronic transport in benzodifuran single-molecule transistors

    Science.gov (United States)

    Xiang, An; Li, Hui; Chen, Songjie; Liu, Shi-Xia; Decurtins, Silvio; Bai, Meilin; Hou, Shimin; Liao, Jianhui

    2015-04-01

    Benzodifuran (BDF) single-molecule transistors have been fabricated in electromigration break junctions for electronic measurements. The inelastic electron tunneling spectrum validates that the BDF molecule is the pathway of charge transport. The gating effect is analyzed in the framework of a single-level tunneling model combined with transition voltage spectroscopy (TVS). The analysis reveals that the highest occupied molecular orbital (HOMO) of the thiol-terminated BDF molecule dominates the charge transport through Au-BDF-Au junctions. Moreover, the energy shift of the HOMO caused by the gate voltage is the main reason for conductance modulation. In contrast, the electronic coupling between the BDF molecule and the gold electrodes, which significantly affects the low-bias junction conductance, is only influenced slightly by the applied gate voltage. These findings will help in the design of future molecular electronic devices.Benzodifuran (BDF) single-molecule transistors have been fabricated in electromigration break junctions for electronic measurements. The inelastic electron tunneling spectrum validates that the BDF molecule is the pathway of charge transport. The gating effect is analyzed in the framework of a single-level tunneling model combined with transition voltage spectroscopy (TVS). The analysis reveals that the highest occupied molecular orbital (HOMO) of the thiol-terminated BDF molecule dominates the charge transport through Au-BDF-Au junctions. Moreover, the energy shift of the HOMO caused by the gate voltage is the main reason for conductance modulation. In contrast, the electronic coupling between the BDF molecule and the gold electrodes, which significantly affects the low-bias junction conductance, is only influenced slightly by the applied gate voltage. These findings will help in the design of future molecular electronic devices. Electronic supplementary information (ESI) available: The fabrication procedure for BDF single

  11. Pentacene Organic-Thin-Film Field-Effect Transistors

    Institute of Scientific and Technical Information of China (English)

    张素梅; 石家纬; 刘明大; 李靖; 郭树旭; 王伟

    2004-01-01

    We have fabricated organic thin-film transistors using the small-molecule polycyclic aromatic hydrocarbon pentacene as an active material. Devices were fabricated on glass substrates by using rf-magnetron sputtered amorphous aluminium as the gate electrode, and gelatinized polyimide as the gate dielectric with physical vapour grown pentacene thin films pasted on it as the active layer, then using rf-magnetron sputtered amorphous aluminium as the source and drain contacts. Field effect mobility and threshold voltage is 0.092 cm2 /Vs and 14.5 V,respectively. On-off current ratio is nearly 103.

  12. Neuro-Space Mapping for Modeling Heterojunction Bipolar Transistor

    Institute of Scientific and Technical Information of China (English)

    Yan Shuxia; Cheng Qianfu; Wu Haifeng; Zhang Qijun

    2015-01-01

    A neuro-space mapping(Neuro-SM) for modeling heterojunction bipolar transistor(HBT) is presented, which can automatically modify the input signals of the given model by neural network. The novel Neuro-SM formu-lations for DC and small-signal simulation are proposed to obtain the mapping network. Simulation results show that the errors between Neuro-SM models and the accurate data are less than 1%, demonstrating that the accurcy of the proposed method is higher than those of the existing models.

  13. Organic single-crystal field-effect transistors

    Directory of Open Access Journals (Sweden)

    Colin Reese

    2007-03-01

    Full Text Available Organic molecular crystals hold great promise for the rational development of organic semiconductor materials. Their long-range order not only reveals the performance limits of organic materials, but also provides unique insight into their intrinsic transport properties. The field-effect transistor (FET has served as a versatile tool for electrical characterization of many facets of their performance. In the last few years, breakthroughs in single-crystal FET fabrication techniques have enabled the realization of field-effect mobilities far surpassing amorphous Si, observation of the Hall effect in an organic material, and the study of transport as an explicit function of molecular packing and chemical structure.

  14. Nanoscale field effect transistor for biomolecular signal amplification

    CERN Document Server

    Chen, Yu; Hong, Mi K; Erramilli, Shyamsunder; Rosenberg, Carol; Mohanty, Pritiraj

    2008-01-01

    We report amplification of biomolecular recognition signal in lithographically defined silicon nanochannel devices. The devices are configured as field effect transistors (FET) in the reversed source-drain bias region. The measurement of the differential conductance of the nanowire channels in the FET allows sensitive detection of changes in the surface potential due to biomolecular binding. Narrower silicon channels demonstrate higher sensitivity to binding due to increased surface-to-volume ratio. The operation of the device in the negative source-drain region demonstrates signal amplification. The equivalence between protein binding and change in the surface potential is described.

  15. Ion-Sensitive Field-Effect Transistor for Biological Sensing

    Directory of Open Access Journals (Sweden)

    Chang-Soo Lee

    2009-09-01

    Full Text Available In recent years there has been great progress in applying FET-type biosensors for highly sensitive biological detection. Among them, the ISFET (ion-sensitive field-effect transistor is one of the most intriguing approaches in electrical biosensing technology. Here, we review some of the main advances in this field over the past few years, explore its application prospects, and discuss the main issues, approaches, and challenges, with the aim of stimulating a broader interest in developing ISFET-based biosensors and extending their applications for reliable and sensitive analysis of various biomolecules such as DNA, proteins, enzymes, and cells.

  16. Bottom-up graphene nanoribbon field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Patrick B. [Applied Science and Technology, University of California, Berkeley, California 94720 (United States); Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States); Pedramrazi, Zahra [Department of Physics, University of California, Berkeley, California 94720 (United States); Madani, Ali [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States); Chen, Yen-Chia; Crommie, Michael F. [Department of Physics, University of California, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720 (United States); Oteyza, Dimas G. de [Department of Physics, University of California, Berkeley, California 94720 (United States); Centro de Física de Materiales CSIC/UPV-EHU-Materials Physics Center, San Sebastián E-20018 (Spain); Chen, Chen [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Fischer, Felix R. [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720 (United States); Bokor, Jeffrey, E-mail: jbokor@eecs.berkeley.edu [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720 (United States)

    2013-12-16

    Recently developed processes have enabled bottom-up chemical synthesis of graphene nanoribbons (GNRs) with precise atomic structure. These GNRs are ideal candidates for electronic devices because of their uniformity, extremely narrow width below 1 nm, atomically perfect edge structure, and desirable electronic properties. Here, we demonstrate nano-scale chemically synthesized GNR field-effect transistors, made possible by development of a reliable layer transfer process. We observe strong environmental sensitivity and unique transport behavior characteristic of sub-1 nm width GNRs.

  17. The design and fabrication on gate type resonant tunneling transistor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In light of fabricating resonant tunneling diode(RTD),in this paper a GaAs-based resonant tunneling transistor with gate structure(GRTT)has been designed and fabricated successfully.A systematic depiction centers on the designs of material structure,device structure,photo lithography mask,fabrication of device and the measurement and analysis of parameters.The fabricated GRTT has a maximum PVCR of 46 and a maximum transconductance of 8 mS.The work lays the foundation for further improvement on the performance and parameters of RTT.

  18. Doping-less Tunnel Field Effect Transistor: Design and Investigation

    OpenAIRE

    Kumar, M. Jagadesh; Janardhanan, Sindhu

    2013-01-01

    Using calibrated simulations, we report a detailed study of the doping-less tunnel field effect transistor (TFET) on a thin intrinsic silicon film using charge plasma concept. Without the need for any doping, the source and drain regions are formed using the charge plasma concept by choosing appropriate work functions for the source and drain metal electrodes. Our results show that the performance of the doping-less TFET is similar to that of a corresponding doped TFET. The doping-less TFET i...

  19. Single-event burnout of power bipolar junction transistors

    International Nuclear Information System (INIS)

    Experimental evidence of single-event burnout of power bipolar junctions transistors (BJTs) is reported for the first time. Several commercial power BJTs were characterized in a simulated cosmic ray environment using mono-energetic ions at the tandem Van de Graaff accelerator facility at Brookhaven National Laboratory. Most of the device types exposed to this simulated environment exhibited burnout behavior. In this paper the experimental technique, data, and results are presented, while a qualitative model is used to help explain those results and trends observed in this experiment

  20. Ferroelectric memory element based on thin film field effect transistor

    Science.gov (United States)

    Poghosyan, A. R.; Aghamalyan, N. R.; Elbakyan, E. Y.; Guo, R.; Hovsepyan, R. K.

    2013-09-01

    We report the preparation and investigation of ferroelectric field effect transistors (FET) using ZnO:Li films with high field mobility of the charge carriers as a FET channel and as a ferroelectric active element simultaneously. The possibility for using of ferroelectric FET based on the ZnO:Li films in the ZnO:Li/LaB6 heterostructure as a bi-stable memory element for information recording is shown. The proposed ferroelectric memory structure does not manifest a fatigue after multiple readout of once recorded information.

  1. Ultra-short suspended single-wall carbon nanotube transistors

    OpenAIRE

    Island, J. O.; Tayari, V.; Yigen, S.; McRae, A. C.; Champagne, A. R.

    2011-01-01

    We describe a method to fabricate clean suspended single-wall carbon nanotube (SWCNT) transistors hosting a single quantum dot ranging in length from a few 10s of nm down to $\\approx$ 3 nm. We first align narrow gold bow-tie junctions on top of individual SWCNTs and suspend the devices. We then use a feedback-controlled electromigration to break the gold junctions and expose nm-sized sections of SWCNTs. We measure electron transport in these devices at low temperature and show that they form ...

  2. Touching polymer chains by organic field-effect transistors

    OpenAIRE

    Wei Shao; Huanli Dong; Zhigang Wang; Wenping Hu

    2014-01-01

    Organic field-effect transistors (OFETs) are used to directly “touch” the movement and dynamics of polymer chains, and then determine Tg. As a molecular-level probe, the conducting channel of OFETs exhibits several unique advantages: 1) it directly detects the motion and dynamics of polymer chain at T g ; 2) it allows the measurement of size effects in ultrathin polymer films (even down to 6 nm), which bridges the gap in understanding effects between surface and interface. This facile and rel...

  3. Electrolyte-gated organic synapse transistor interfaced with neurons

    CERN Document Server

    Desbief, Simon; Casalini, Stefano; Guerin, David; Tortorella, Silvia; Barbalinardo, Marianna; Kyndiah, Adrica; Murgia, Mauro; Cramer, Tobias; Biscarini, Fabio; Vuillaume, Dominique

    2016-01-01

    We demonstrate an electrolyte-gated hybrid nanoparticle/organic synapstor (synapse-transistor, termed EGOS) that exhibits short-term plasticity as biological synapses. The response of EGOS makes it suitable to be interfaced with neurons: short-term plasticity is observed at spike voltage as low as 50 mV (in a par with the amplitude of action potential in neurons) and with a typical response time in the range of tens milliseconds. Human neuroblastoma stem cells are adhered and differentiated into neurons on top of EGOS. We observe that the presence of the cells does not alter short-term plasticity of the device.

  4. Graded index SCH transistor laser: Analysis of various confinement structures

    CERN Document Server

    Hosseini, Mohammad; Taghavi, Iman

    2016-01-01

    New configuration of confinement structure is utilized to improve optoelectronic performances, including threshold current, AC current gain as well as optical bandwidth and optical output power of single quantum well transistor laser. Considering the drift component in addition to the diffusion term in electron current density, a new continuity equation is developed to analyze the proposed structures. Physical parameters including, electron mobility, recombination lifetime, optical confinement factor, electron capture time and photon lifetime is calculated for new structures. Based on solving continuity equation in separate confinement heterostructures, threshold current reduces 67% and optical output power increases 37%.

  5. Characterization of a Common-Gate Amplifier Using Ferroelectric Transistors

    Science.gov (United States)

    Hunt, Mitchell; Sayyah, Rana; MacLeod, Todd C.; Ho, Fat D.

    2011-01-01

    In this paper, the empirical data collected through experiments performed using a FeFET in the common-gate amplifier circuit is presented. The FeFET common-gate amplifier was characterized by varying all parameters in the circuit, such as load resistance, biasing of the transistor, and input voltages. Due to the polarization of the ferroelectric layer, the particular behavior of the FeFET common-gate amplifier presents interesting results. Furthermore, the differences between a FeFET common-gate amplifier and a MOSFET common-gate amplifier are examined.

  6. Transistor Devices 7kW AC/DC电源

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Transistor Devices公司推出LCPM系列7kW液体冷却电源模块,每个模块的尺寸为2″×2.8×″(11.6W每立方英寸),因此六个并排置于17.5″架子上的模块可以自平衡的3相国际电源(195V AC至265V AC-47-63周期)传递达42kW的稳定电源。

  7. Ambipolar transistors based on random networks of WS2 nanotubes

    Science.gov (United States)

    Sugahara, Mitsunari; Kawai, Hideki; Yomogida, Yohei; Maniwa, Yutaka; Okada, Susumu; Yanagi, Kazuhiro

    2016-07-01

    WS2 nanotubes are rolled multiwalled nanotubes made of a layered material, tungsten disulfide. Their fibril structures enable the fabrication of random network films; however, these films are nonconducting, and thus have not been used for electronic applications. Here, we demonstrate that carrier injection into WS2 networks using an electrolyte gating approach could cause these networks to act as semiconducting channels. We clarify the Raman characteristics of WS2 nanotubes under electrolyte gating and confirm the feasibility of the injection of electrons and holes. We reveal ambipolar behaviors of the WS2 nanotube networks in field-effect transistor setups with electrolyte gating.

  8. Three-Dimensional Insulated Gate Bipolar Transistor (IGBT) Development

    OpenAIRE

    Gilbert, P.V.; Neudeck, G. W.

    1992-01-01

    A new insulated gate bipolar transistor structure, the 3D-IGBT, is presented. The 3D-IGBT utilizes selective epitaxial silicon to form a top contacted anode and still retain the cellular structure of vemcally oriented devices. The 3D-IGBT , unlike other fully integrable power devices, exploits the merits of cellular structure to increase its packing density and thus reduce its on-resistance per unit area. It also eliminates the parasitic JFET resistance found in vertical IGBT's. To integrate ...

  9. Characteristics of voltage regulators with serial NPN transistor in the fields of medium and high energy photons

    International Nuclear Information System (INIS)

    Variation of collector - emitter dropout voltage on serial transistors of voltage regulators LM2990T-5 and LT1086CT5 were used as the parameter for detection of examined devices' radiation hardness in X and ? radiation fields. Biased voltage regulators with serial super-β transistor in the medium dose rate X radiation field had significantly different response from devices with conventional serial NPN transistor. Although unbiased components suffered greater damage in most cases, complete device failure happened only among the biased components with serial super-β transistor in Bremsstrahlung field. Mechanisms of transistors degradation in ionizing radiation fields were analysed

  10. The Bipolar Field-Effect Transistor: ⅩⅢ. Physical Realizations of the Transistor and Circuits (One-Two-MOS-Gates on Thin-Thick Pure-Impure Base)

    Institute of Scientific and Technical Information of China (English)

    薩支唐; 揭斌斌

    2009-01-01

    This paper reports the physical realization of the Bipolar Field-Effect Transistor (BiFET) and its one-transistor basic building block circuits. Examples are given for the one and two MOS gates on thin and thick, pure and impure base, with electron and hole contacts, and the corresponding theoretical current-voltage characteristics previously computed by us, without generation-recombination-trapping-tunneling of electrons and holes. These ex-amples include the one-MOS-gate on semi-infinite thick impure base transistor (the bulk transistor) and the impure-thin-base Silicon-on-Insulator (SOI) transistor and the two-MOS-gates on thin base transistors (the FinFET and the Thin Film Transistor TFT). Figures are given with the cross-section views containing the electron and hole concen-tration and current density distributions and trajectories and the corresponding DC current-voltage characteristics.

  11. Temperature Dependence of Field-Effect Mobility in Organic Thin-Film Transistors: Similarity to Inorganic Transistors.

    Science.gov (United States)

    Okada, Jun; Nagase, Takashi; Kobayashi, Takashi; Naito, Hiroyoshi

    2016-04-01

    Carrier transport in solution-processed organic thin-film transistors (OTFTs) based on dioctylbenzothienobenzothiophene (C8-BTBT) has been investigated in a wide temperature range from 296 to 10 K. The field-effect mobility shows thermally activated behavior whose activation energy becomes smaller with decreasing temperature. The temperature dependence of field-effect mobility found in C8-BTBT is similar to that of others materials: organic semiconducting polymers, amorphous oxide semiconductors and hydrogenated amorphous silicon. These results indicate that hopping transport between isoenergetic localized states becomes dominated in a low temperature regime in these materials. PMID:27451607

  12. Method for Providing Semiconductors Having Self-Aligned Ion Implant

    Science.gov (United States)

    Neudeck, Philip G. (Inventor)

    2014-01-01

    A method is disclosed that provides a self-aligned nitrogen-implant particularly suited for a Junction Field Effect Transistor (JFET) semiconductor device preferably comprised of a silicon carbide (SiC). This self-aligned nitrogen-implant allows for the realization of durable and stable electrical functionality of high temperature transistors such as JFETs. The method implements the self-aligned nitrogen-implant having predetermined dimensions, at a particular step in the fabrication process, so that the SiC junction field effect transistors are capable of being electrically operating continuously at 500.degree. C. for over 10,000 hours in an air ambient with less than a 10% change in operational transistor parameters.

  13. Flexible graphene transistors for recording cell action potentials

    Science.gov (United States)

    Blaschke, Benno M.; Lottner, Martin; Drieschner, Simon; Bonaccini Calia, Andrea; Stoiber, Karolina; Rousseau, Lionel; Lissourges, Gaëlle; Garrido, Jose A.

    2016-06-01

    Graphene solution-gated field-effect transistors (SGFETs) are a promising platform for the recording of cell action potentials due to the intrinsic high signal amplification of graphene transistors. In addition, graphene technology fulfills important key requirements for in-vivo applications, such as biocompability, mechanical flexibility, as well as ease of high density integration. In this paper we demonstrate the fabrication of flexible arrays of graphene SGFETs on polyimide, a biocompatible polymeric substrate. We investigate the transistor’s transconductance and intrinsic electronic noise which are key parameters for the device sensitivity, confirming that the obtained values are comparable to those of rigid graphene SGFETs. Furthermore, we show that the devices do not degrade during repeated bending and the transconductance, governed by the electronic properties of graphene, is unaffected by bending. After cell culture, we demonstrate the recording of cell action potentials from cardiomyocyte-like cells with a high signal-to-noise ratio that is higher or comparable to competing state of the art technologies. Our results highlight the great capabilities of flexible graphene SGFETs in bioelectronics, providing a solid foundation for in-vivo experiments and, eventually, for graphene-based neuroprosthetics.

  14. Carbon nanotube transistor based high-frequency electronics

    Science.gov (United States)

    Schroter, Michael

    At the nanoscale carbon nanotubes (CNTs) have higher carrier mobility and carrier velocity than most incumbent semiconductors. Thus CNT based field-effect transistors (FETs) are being considered as strong candidates for replacing existing MOSFETs in digital applications. In addition, the predicted high intrinsic transit frequency and the more recent finding of ways to achieve highly linear transfer characteristics have inspired investigations on analog high-frequency (HF) applications. High linearity is extremely valuable for an energy efficient usage of the frequency spectrum, particularly in mobile communications. Compared to digital applications, the much more relaxed constraints for CNT placement and lithography combined with already achieved operating frequencies of at least 10 GHz for fabricated devices make an early entry in the low GHz HF market more feasible than in large-scale digital circuits. Such a market entry would be extremely beneficial for funding the development of production CNTFET based process technology. This talk will provide an overview on the present status and feasibility of HF CNTFET technology will be given from an engineering point of view, including device modeling, experimental results, and existing roadblocks. Carbon nanotube transistor based high-frequency electronics.

  15. Nano-textured high sensitivity ion sensitive field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Hajmirzaheydarali, M.; Sadeghipari, M.; Akbari, M.; Shahsafi, A.; Mohajerzadeh, S., E-mail: mohajer@ut.ac.ir [Thin Film and Nanoelectronics Lab, Nanoelectronics Center of Excellence, School of Electrical and Computer Engineering, University of Tehran, Tehran 143957131 (Iran, Islamic Republic of)

    2016-02-07

    Nano-textured gate engineered ion sensitive field effect transistors (ISFETs), suitable for high sensitivity pH sensors, have been realized. Utilizing a mask-less deep reactive ion etching results in ultra-fine poly-Si features on the gate of ISFET devices where spacing of the order of 10 nm and less is achieved. Incorporation of these nano-sized features on the gate is responsible for high sensitivities up to 400 mV/pH in contrast to conventional planar structures. The fabrication process for this transistor is inexpensive, and it is fully compatible with standard complementary metal oxide semiconductor fabrication procedure. A theoretical modeling has also been presented to predict the extension of the diffuse layer into the electrolyte solution for highly featured structures and to correlate this extension with the high sensitivity of the device. The observed ultra-fine features by means of scanning electron microscopy and transmission electron microscopy tools corroborate the theoretical prediction.

  16. Polymer transistors fabricated by painting of metallic nanoparticles

    Science.gov (United States)

    Li, S. P.; Russell, D. M.; Newsome, C. J.; Kugler, T.; Shimoda, T.

    2006-09-01

    In this letter the authors describe the fabrication of high performance polymer thin film transistors using an aqueous based silver colloid to form source and drain electrodes patterned by brush painting. The electrode dimensions were controlled by a surface energy pattern defined by soft contact printing of a self-assembled monolayer 1H,1H,2H,2H-perfluorodecyl-trichlorosilane on a SiO2 surface which acted as a dewetting layer for the painted silver particle suspension. Another self-assembled monolayer of 1H ,1H,2H,2H-perfluorodecanethiol was also used to increase the work function of the patterned silver electrodes in order to decrease the barrier for charge injection into the polymer semiconductor. The field-effect mobility of the thin film transistors fabricated by this method approached 0.02cm2V-1s-1 with an on/off current ratio of 105. The relative high mobility may be influenced by the ordering of the poly(3-hexylthiophene) semiconductor layer by the self-assembled monolayer used to define the source and drain electrodes.

  17. Silicon junctionless field effect transistors as room temperature terahertz detectors

    Energy Technology Data Exchange (ETDEWEB)

    Marczewski, J., E-mail: jmarcz@ite.waw.pl; Tomaszewski, D.; Zaborowski, M. [Institute of Electron Technology, al. Lotnikow 32/46, 02-668 Warsaw (Poland); Knap, W. [Institute of High Pressure Physics of the Polish Academy of Sciences, ul. Sokolowska 29/37, 01-142 Warsaw (Poland); Laboratory Charles Coulomb, Montpellier University & CNRS, Place E. Bataillon, Montpellier 34095 (France); Zagrajek, P. [Institute of Optoelectronics, Military University of Technology, ul. gen. S. Kaliskiego 2, 00-908 Warsaw (Poland)

    2015-09-14

    Terahertz (THz) radiation detection by junctionless metal-oxide-semiconductor field-effect transistors (JL MOSFETs) was studied and compared with THz detection using conventional MOSFETs. It has been shown that in contrast to the behavior of standard transistors, the junctionless devices have a significant responsivity also in the open channel (low resistance) state. The responsivity for a photolithographically defined JL FET was 70 V/W and the noise equivalent power 460 pW/√Hz. Working in the open channel state may be advantageous for THz wireless and imaging applications because of its low thermal noise and possible high operating speed or large bandwidth. It has been proven that the junctionless MOSFETs can also operate in a zero gate bias mode, which enables simplification of the THz array circuitry. Existing models of THz detection by MOSFETs were considered and it has been demonstrated that the process of detection by these junctionless devices cannot be explained within the framework of the commonly accepted models and therefore requires a new theoretical approach.

  18. Degradation mechanisms of current gain in NPN transistors

    Science.gov (United States)

    Li, Xing-Ji; Geng, Hong-Bin; Lan, Mu-Jie; Yang, De-Zhuang; He, Shi-Yu; Liu, Chao-Ming

    2010-06-01

    An investigation of ionization and displacement damage in silicon NPN bipolar junction transistors (BJTs) is presented. The transistors were irradiated separately with 90-keV electrons, 3-MeV protons and 40-MeV Br ions. Key parameters were measured in-situ and the change in current gain of the NPN BJTS was obtained at a fixed collector current (Ic = 1 mA). To characterise the radiation damage of NPN BJTs, the ionizing dose Di and displacement dose Dd as functions of chip depth in the NPN BJTs were calculated using the SRIM and Geant4 code for protons, electrons and Br ions, respectively. Based on the discussion of the radiation damage equation for current gain, it is clear that the current gain degradation of the NPN BJTs is sensitive to both ionization and displacement damage. The degradation mechanism of the current gain is related to the ratio of Dd/(Dd + Di) in the sensitive region given by charged particles. The irradiation particles leading to lower Dd/(Dd + Di) within the same chip depth at a given total dose would mainly produce ionization damage to the NPN BJTs. On the other hand, the charged particles causing larger Dd/(Dd + Di) at a given total dose would tend to generate displacement damage to the NPN BJTs. The Messenger-Spratt equation could be used to describe the experimental data for the latter case.

  19. Development of solution-gated graphene transistor model for biosensors.

    Science.gov (United States)

    Karimi, Hediyeh; Yusof, Rubiyah; Rahmani, Rasoul; Hosseinpour, Hoda; Ahmadi, Mohammad T

    2014-01-01

    : The distinctive properties of graphene, characterized by its high carrier mobility and biocompatibility, have stimulated extreme scientific interest as a promising nanomaterial for future nanoelectronic applications. In particular, graphene-based transistors have been developed rapidly and are considered as an option for DNA sensing applications. Recent findings in the field of DNA biosensors have led to a renewed interest in the identification of genetic risk factors associated with complex human diseases for diagnosis of cancers or hereditary diseases. In this paper, an analytical model of graphene-based solution gated field effect transistors (SGFET) is proposed to constitute an important step towards development of DNA biosensors with high sensitivity and selectivity. Inspired by this fact, a novel strategy for a DNA sensor model with capability of single-nucleotide polymorphism detection is proposed and extensively explained. First of all, graphene-based DNA sensor model is optimized using particle swarm optimization algorithm. Based on the sensing mechanism of DNA sensors, detective parameters (Ids and Vgmin) are suggested to facilitate the decision making process. Finally, the behaviour of graphene-based SGFET is predicted in the presence of single-nucleotide polymorphism with an accuracy of more than 98% which guarantees the reliability of the optimized model for any application of the graphene-based DNA sensor. It is expected to achieve the rapid, quick and economical detection of DNA hybridization which could speed up the realization of the next generation of the homecare sensor system. PMID:24517158

  20. Potential of carbon nanotube field effect transistors for analogue circuits

    KAUST Repository

    Hayat, Khizar

    2013-05-11

    This Letter presents a detailed comparison of carbon nanotube field effect transistors (CNFETs) and metal oxide semiconductor field effect transistors (MOSFETs) with special focus on carbon nanotube FET\\'s potential for implementing analogue circuits in the mm-wave and sub-terahertz range. The latest CNFET lithographic dimensions place it at-par with complementary metal oxide semiconductor in terms of current handling capability, whereas the forecasted improvement in the lithography enables the CNFETs to handle more than twice the current of MOSFETs. The comparison of RF parameters shows superior performance of CNFETs with a g m , f T and f max of 2.7, 2.6 and 4.5 times higher, respectively. MOSFET- and CNFET-based inverter, three-stage ring oscillator and LC oscillator have been designed and compared as well. The CNFET-based inverters are found to be ten times faster, the ring oscillator demonstrates three times higher oscillation frequency and CNFET-based LC oscillator also shows improved performance than its MOSFET counterpart.

  1. Cylindrical Field Effect Transistor: A Full Volume Inversion Device

    KAUST Repository

    Fahad, Hossain M.

    2010-12-01

    The increasing demand for high performance as well as low standby power devices has been the main reason for the aggressive scaling of conventional CMOS transistors. Current devices are at the 32nm technology node. However, due to physical limitations as well as increase in short-channel effects, leakage, power dissipation, this scaling trend cannot continue and will eventually hit a barrier. In order to overcome this, alternate device topologies have to be considered altogether. Extensive research on ultra thin body double gate FETs and gate all around nanowire FETs has shown a lot of promise. Under strong inversion, these devices have demonstrated increased performance over their bulk counterparts. This is mainly attributed to full carrier inversion in the body. However, these devices are still limited by lithographic and processing challenges making them unsuitable for commercial production. This thesis explores a unique device structure called the CFET (Cylindrical Field Effect Transistors) which also like the above, relies on complete inversion of carriers in the body/bulk. Using dual gates; an outer and an inner gate, full-volume inversion is possible with benefits such as enhanced drive currents, high Ion/Ioff ratios and reduced short channel effects.

  2. Compact model for switching characteristics of graphene field effect transistor

    Science.gov (United States)

    Sreenath, R.; Bala Tripura Sundari, B.

    2016-04-01

    The scaling of CMOS transistors has resulted in intensified short channel effects, indicating that CMOS has reached its physical limits. Alternate non silicon based materials namely carbon based graphene, carbon nanotubes are being explored for usability as channel and interconnect material due to their established higher mobility and robustness. This paper presents a drift-diffusion based circuit simulatable Verilog-A compact model of graphene field effect transistor (GFET) for channel length of 100nm.The focus is on the development of simulatable device model in Verilog A based on intrinsic parameters and obtain the current, high cutoff frequency and use the model into circuit level simulations to realize an inverter and a 3-stage ring oscillator using Synopsys HSPICE. The applications are so chosen that their switching characteristics enable the determination of the RF frequency ranges of operation that the model can achieve when used in digital applications and also to compare its performance with existing CMOS model. The GFET's switching characteristics and power consumption were found to be better than similarly sized CMOS operating at same range of voltages. The basic frequency of operation in the circuit is of significant importance so as to use the model in other applications at RF and in future for millimeter wave applications. The frequency of operation at circuit level is found to be 1.1GHz at 100nm which is far higher than the existing frequency of 245 MHz reported at 500nm using AlN.

  3. Introduction to thin film transistors physics and technology of TFTs

    CERN Document Server

    Brotherton, S D

    2013-01-01

    Introduction to Thin Film Transistors reviews the operation, application, and technology of the main classes of thin film transistor (TFT) of current interest for large area electronics. The TFT materials covered include hydrogenated amorphous silicon (a-Si:H), poly-crystalline silicon (poly-Si), transparent amorphous oxide semiconductors (AOS), and organic semiconductors. The large scale manufacturing of a-Si:H TFTs forms the basis of the active matrix flat panel display industry. Poly-Si TFTs facilitate the integration of electronic circuits into portable active matrix liquid crystal displays, and are increasingly used in active matrix organic light emitting diode (AMOLED) displays for smart phones. The recently developed AOS TFTs are seen as an alternative option to poly-Si and a-Si:H for AMOLED TV and large AMLCD TV applications, respectively. The organic TFTs are regarded as a cost effective route into flexible electronics. As well as treating the highly divergent preparation and properties of these mat...

  4. Silicon junctionless field effect transistors as room temperature terahertz detectors

    International Nuclear Information System (INIS)

    Terahertz (THz) radiation detection by junctionless metal-oxide-semiconductor field-effect transistors (JL MOSFETs) was studied and compared with THz detection using conventional MOSFETs. It has been shown that in contrast to the behavior of standard transistors, the junctionless devices have a significant responsivity also in the open channel (low resistance) state. The responsivity for a photolithographically defined JL FET was 70 V/W and the noise equivalent power 460 pW/√Hz. Working in the open channel state may be advantageous for THz wireless and imaging applications because of its low thermal noise and possible high operating speed or large bandwidth. It has been proven that the junctionless MOSFETs can also operate in a zero gate bias mode, which enables simplification of the THz array circuitry. Existing models of THz detection by MOSFETs were considered and it has been demonstrated that the process of detection by these junctionless devices cannot be explained within the framework of the commonly accepted models and therefore requires a new theoretical approach

  5. Nano-textured high sensitivity ion sensitive field effect transistors

    International Nuclear Information System (INIS)

    Nano-textured gate engineered ion sensitive field effect transistors (ISFETs), suitable for high sensitivity pH sensors, have been realized. Utilizing a mask-less deep reactive ion etching results in ultra-fine poly-Si features on the gate of ISFET devices where spacing of the order of 10 nm and less is achieved. Incorporation of these nano-sized features on the gate is responsible for high sensitivities up to 400 mV/pH in contrast to conventional planar structures. The fabrication process for this transistor is inexpensive, and it is fully compatible with standard complementary metal oxide semiconductor fabrication procedure. A theoretical modeling has also been presented to predict the extension of the diffuse layer into the electrolyte solution for highly featured structures and to correlate this extension with the high sensitivity of the device. The observed ultra-fine features by means of scanning electron microscopy and transmission electron microscopy tools corroborate the theoretical prediction

  6. Optimization of ultra-low-power CMOS transistors

    CERN Document Server

    Stockinger, M

    2000-01-01

    chosen suitable for ultra-low-power purposes. In a first optimization study the drive current of NMOS transistors is maximized while keeping the leakage current below a limit of 1 pA/mu m. This results in peaking channel doping devices (PCD) with narrow doping peaks placed asymmetrically in the channel. Drive current improvements of 45 % and 71 % for the 0.25 mu m and 0.1 mu m devices, respectively, are achieved compared to uniformly doped devices. The PCD device is studied in detail and explanations for its superior drive performance are given. It is compared to already known device structures and practical alternatives are suggested with respect to its manufacturability. In a second optimization study the gate delay times of complete CMOS inverters are minimized. Both the doping profiles of the NMOS and PMOS transistors are optimized at the same time which results again in PCD devices. The inverter speeds are improved by 54 % and 97 % for the 0.25 mu m and 0.1 mu m devices, respectively. Ultra-low-power CMO...

  7. Modeling and simulation study of novel Double Gate Ferroelectric Junctionless (DGFJL) transistor

    Science.gov (United States)

    Mehta, Hema; Kaur, Harsupreet

    2016-09-01

    In this work we have proposed an analytical model for Double Gate Ferroelectric Junctionless Transistor (DGFJL), a novel device, which incorporates the advantages of both Junctionless (JL) transistor and Negative Capacitance phenomenon. A complete drain current model has been developed by using Landau-Khalatnikov equation and parabolic potential approximation to analyze device behavior in different operating regions. It has been demonstrated that DGFJL transistor acts as a step-up voltage transformer and exhibits subthreshold slope values less than 60 mV/dec. In order to assess the advantages offered by the proposed device, extensive comparative study has been done with equivalent Double Gate Junctionless Transistor (DGJL) transistor with gate insulator thickness same as ferroelectric gate stack thickness of DGFJL transistor. It is shown that incorporation of ferroelectric layer can overcome the variability issues observed in JL transistors. The device has been studied over a wide range of parameters and bias conditions to comprehensively investigate the device design guidelines to obtain a better insight into the application of DGFJL as a potential candidate for future technology nodes. The analytical results so derived from the model have been verified with simulated results obtained using ATLAS TCAD simulator and a good agreement has been found.

  8. A steep-slope transistor based on abrupt electronic phase transition

    Science.gov (United States)

    Shukla, Nikhil; Thathachary, Arun V.; Agrawal, Ashish; Paik, Hanjong; Aziz, Ahmedullah; Schlom, Darrell G.; Gupta, Sumeet Kumar; Engel-Herbert, Roman; Datta, Suman

    2015-08-01

    Collective interactions in functional materials can enable novel macroscopic properties like insulator-to-metal transitions. While implementing such materials into field-effect-transistor technology can potentially augment current state-of-the-art devices by providing unique routes to overcome their conventional limits, attempts to harness the insulator-to-metal transition for high-performance transistors have experienced little success. Here, we demonstrate a pathway for harnessing the abrupt resistivity transformation across the insulator-to-metal transition in vanadium dioxide (VO2), to design a hybrid-phase-transition field-effect transistor that exhibits gate controlled steep (`sub-kT/q') and reversible switching at room temperature. The transistor design, wherein VO2 is implemented in series with the field-effect transistor's source rather than into the channel, exploits negative differential resistance induced across the VO2 to create an internal amplifier that facilitates enhanced performance over a conventional field-effect transistor. Our approach enables low-voltage complementary n-type and p-type transistor operation as demonstrated here, and is applicable to other insulator-to-metal transition materials, offering tantalizing possibilities for energy-efficient logic and memory applications.

  9. Multivibrator transistor switch module using a high-temperature superconducting core

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, T.; Shibata, T.; Makino, M.; Mohri, K. (Department of Electrical Engineering, Nagoya University, Nagoya 464 (Japan))

    1991-11-15

    A new high-speed transistor switch module is presented using YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} high-temperature superconductor (HTcSC) bulk cores in liquid nitrogen. A Royer oscillator-type magnetic multivibrator is constructed using two switching transistors combined with four windings tightly set around a HTcSC disk core. Oscillation of the multivibrator is initiated by applying an ON signal pulse current ({ital I}{sub ON}) to a coil, and terminated by applying an OFF signal pulse current ({ital I}{sub OFF}) to a small transistor which shorts another coil of the HTcSC core. The multivibrator transistor module switched with a turn-on time {ital t}{sub ON} of about 0.2 {mu}s and a turn-off time {ital t}{sub OFF} of about 0.2 {mu}s for 1-A transistors. The values of {ital t}{sub ON} and {ital t}{sub OFF} are about 1/10 and 1/100 that of the multivibrator transistor module using an amorphous ferromagnetic core. This quick switching property can be attributed to the Meissner effect or zero inductance effect. These high-speed transistor switching modules have applications in control of small motors with a high rotation speed.

  10. Power lateral pnp transistor operating with high current density in irradiated voltage regulator

    Directory of Open Access Journals (Sweden)

    Vukić Vladimir Đ.

    2013-01-01

    Full Text Available The operation of power lateral pnp transistors in gamma radiation field was examined by detection of the minimum dropout voltage on heavily loaded low-dropout voltage regulators LM2940CT5, clearly demonstrating their low radiation hardness, with unacceptably low values of output voltage and collector-emitter voltage volatility. In conjunction with previous results on base current and forward emitter current gain of serial transistors, it was possible to determine the positive influence of high load current on a slight improvement of voltage regulator LM2940CT5 radiation hardness. The high-current flow through the wide emitter aluminum contact of the serial transistor above the isolation oxide caused intensive annealing of the positive oxide-trapped charge, leading to decrease of the lateral pnp transistor's current gain, but also a more intensive recovery of the small-signal npn transistors in the control circuit. The high current density in the base area of the lateral pnp transistor immediately below the isolation oxide decreased the concentration of negative interface traps. Consequently, the positive influence of the reduced concentration of the oxide-trapped charge on the negative feedback reaction circuit, together with the favourable effect of reduced interface traps concentration, exceeded negative influence of the annealed oxide-trapped charge on the serial pnp transistor's forward emitter current gain.

  11. Cryogenic preamplification of a single-electron-transistor using a silicon-germanium heterojunction-bipolar-transistor

    International Nuclear Information System (INIS)

    We examine a silicon-germanium heterojunction bipolar transistor (HBT) for cryogenic pre-amplification of a single electron transistor (SET). The SET current modulates the base current of the HBT directly. The HBT-SET circuit is immersed in liquid helium, and its frequency response from low frequency to several MHz is measured. The current gain and the noise spectrum with the HBT result in a signal-to-noise-ratio (SNR) that is a factor of 10–100 larger than without the HBT at lower frequencies. The transition frequency defined by SNR = 1 has been extended by as much as a factor of 10 compared to without the HBT amplification. The power dissipated by the HBT cryogenic pre-amplifier is approximately 5 nW to 5 μW for the investigated range of operation. The circuit is also operated in a single electron charge read-out configuration in the time-domain as a proof-of-principle demonstration of the amplification approach for single spin read-out

  12. Retos Sobre el Modelado del Transistor de Compuerta Flotante de Múltiples Entradas en Circuitos Integrados

    Directory of Open Access Journals (Sweden)

    Agustín Santiago Medina Vázquez

    2012-11-01

    Full Text Available En este artículo se presentan las consideraciones que hay que adoptar para el uso del transistor de compuerta flotante de múltiples entradas para el diseño de circuitos integrados analógicos. Para ello se presentan las principales características de este transistor así como sus principales ventajas con respecto al transistor MOSFET convencional que este dispositivo ofrece. También, se exponen los principales problemas que han frenado el uso de este dispositivo en el ámbito comercial debido a la falta de modelos precisos.

  13. High mobility polymer gated organic field effect transistor using zinc phthalocyanine

    Indian Academy of Sciences (India)

    K R Rajesh; V Kannan; M R Kim; Y S Chae; J K Rhee

    2014-02-01

    Organic thin film transistors were fabricated using evaporated zinc phthalocyanine as the active layer. Parylene film prepared by chemical vapour deposition was used as the organic gate insulator. The annealing of the samples was performed at 120°C for 3 h. At room temperature, these transistors exhibit -type conductivity with field-effect mobilities ranging from 0.025–0.037 cm2/Vs and a (on/off) ratio of ∼ 103. The effect of annealing on transistor characteristics is discussed.

  14. Application of Carbon nano tube field-effect transistor as sensor in analyzing of integrated circuits

    International Nuclear Information System (INIS)

    The purpose of this investigation is to develop a current-transport model for Carbon nano tube field effect transistor applicable in the analysis of detection of chemical material. We implemented an efficient numerical model of a Carbon nano tube field-effect transistor with regard to ultrasonic nano welding treatment. Our results have shown a strong dependence of the I-V characteristics on the wrapping angle and diameter of Carbon nano tubes. Also our calculations have indicated that Carbon nano tube field effect transistors based sensors are promising compact ultra-sensitive and ultra low-power advanced miniaturized sensors in comparison to conventional sensors.

  15. Total dose radiation effects on SOI NMOS transistors with different layouts

    Institute of Scientific and Technical Information of China (English)

    TIAN Hao; ZHANG Zheng-Xuan; HE Wei; YU Wen-Jie; WANG Ru; CHEN Ming

    2008-01-01

    Partially-depleted Silicon-On-Insulator Negative Channel Metal Oxide Semiconductor (SOI NMOS)transistors with different layouts are fabricated on radiation hard Separation by IMplanted OXygen (SIMOX)substrate and tested using 10 keV X-ray radiation sources.The radiation performance is characterized by transistor threshold voltage shift and transistor leakage currents as a function of the total dose up to 2.0×106 rad(Si).The results show that the total dose radiation effects on NMOS devices are very sensitive to their layout structures.

  16. Simulation of quantum-well slipping effect on optical bandwidth in transistor laser

    Institute of Scientific and Technical Information of China (English)

    Hassan Kaatuzian; Seyed Iman Taghavi

    2009-01-01

    An optical bandwidth analysis of a quantum-well(16 nm)transistor laser with 150-μm cavity length using a charge control model is reported in order to modify the quantum-well location through the base region.At constant bias current,the simulation shows significant enhancement in optical bandwidth due to moving the quantum well in the direction of collector-base junction.No remarkable resonance peak,limiting factor in laser diodes,is observed during this modification in transistor laser structure.The method can be utilized for transistor laser structure design.

  17. Electronic transport at semiconductor surfaces - from point-contact transistor to micro-four-point probes

    DEFF Research Database (Denmark)

    Hasegawa, S.; Grey, Francois

    2002-01-01

    The electrical properties of semiconductor surfaces have played a decisive role in one of the most important discoveries of the last century, transistors. In the 1940s, the concept of surface states-new electron energy levels characteristic of the surface atoms-was instrumental in the fabrication...... of the first point-contact transistors, and led to the successful fabrication of field-effect transistors. However, to this day, one property of semiconductor surface states remains poorly understood, both theoretically and experimentally. That is the conduction of electrons or holes directly through...

  18. Fabrication-Technology Research of New Type Silicon Magnetic-Sensitive Transistor

    Institute of Scientific and Technical Information of China (English)

    Xiaofeng Zhao; Dianzhong Wen

    2006-01-01

    This paper mainly describes a research of fabrication-technology of silicon magnetic-sensitive transistor (SMST) with rectangle-plank-cubic structure fabricated on silicon wafer by MEMS technique. An experiment research on basic characteristic of the silicon magnetic-sensitive transistor was done. Anisotropic etching and reliable technique project were provided and applied in order to fabricate SMST with rectangle-plank-cubic construction. This means that a new kind of fabrication technology for silicon magnetic-sensitive transistor was provided. The result shows that the technique can be not only compatible with IC technology but also integrated easily, and has a wide application field.

  19. Principles of transistor circuits introduction to the design of amplifiers, receivers and digital circuits

    CERN Document Server

    Amos, S W

    1990-01-01

    Principles of Transistor Circuits, Seventh Edition discusses the fundamental concepts of transistor circuits. The book is comprised of 16 chapters that cover amplifiers, oscillators, and generators. Chapter 1 discusses semiconductors and junction nodes, while Chapter 2 covers the basic principles of transistors. The subsequent chapters focus on amplifiers, where one of the chapters discusses bias and D.C. The book also talks about sinusoidal oscillators and covers modulators, demodulators, mixers, and receivers. Chapters 13 and 14 discuss pulse generators and sawtooth generators, respectively.

  20. Fabrication and electrical properties of single wall carbon nanotube channel and graphene electrode based transistors arrays

    Energy Technology Data Exchange (ETDEWEB)

    Seo, M.; Kim, H.; Kim, Y. H.; Yun, H.; McAllister, K.; Lee, S. W., E-mail: leesw@konkuk.ac.kr [Division of Quantum Phases and Devices, School of Physics, Konkuk University, Seoul 143-701 (Korea, Republic of); Na, J.; Kim, G. T. [School of Electrical Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Lee, B. J.; Kim, J. J.; Jeong, G. H. [Department of Nano Applied Engineering, Kangwon National University, Kangwon-do 200-701 (Korea, Republic of); Lee, I.; Kim, K. S. [Department of Physics and Graphene Research Institute, Sejong University, Seoul 143-747 (Korea, Republic of)

    2015-07-20

    A transistor structure composed of an individual single-walled carbon nanotube (SWNT) channel with a graphene electrode was demonstrated. The integrated arrays of transistor devices were prepared by transferring patterned graphene electrode patterns on top of the aligned SWNT along one direction. Both single and multi layer graphene were used for the electrode materials; typical p-type transistor and Schottky diode behavior were observed, respectively. Based on our fabrication method and device performances, several issues are suggested and discussed to improve the device reliability and finally to realize all carbon based future electronic systems.

  1. Self-standing chitosan films as dielectrics in organic thin-film transistors

    Directory of Open Access Journals (Sweden)

    J. Morgado

    2013-12-01

    Full Text Available Organic thin film transistors, using self-standing 50 µm thick chitosan films as dielectric, are fabricated using sublimed pentacene or two conjugated polymers deposited by spin coating as semiconductors. Field-effect mobilities are found to be similar to values obtained with other dielectrics and, in the case of pentacene, a value (0.13 cm2/(V•s comparable to high performing transistors was determined. In spite of the low On/Off ratios (a maximum value of 600 was obtained for the pentacene-based transistors, these are promising results for the area of sustainable organic electronics in general and for biocompatible electronics in particular.

  2. Paired-pulse facilitation achieved in protonic/electronic hybrid indium gallium zinc oxide synaptic transistors

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Li Qiang, E-mail: guoliqiang@ujs.edu.cn; Ding, Jian Ning; Huang, Yu Kai [Micro/Nano Science & Technology Center, Jiangsu University, Zhenjiang, 212013 (China); Zhu, Li Qiang, E-mail: lqzhu@nimte.ac.cn [Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

    2015-08-15

    Neuromorphic devices with paired pulse facilitation emulating that of biological synapses are the key to develop artificial neural networks. Here, phosphorus-doped nanogranular SiO{sub 2} electrolyte is used as gate dielectric for protonic/electronic hybrid indium gallium zinc oxide (IGZO) synaptic transistor. In such synaptic transistors, protons within the SiO{sub 2} electrolyte are deemed as neurotransmitters of biological synapses. Paired-pulse facilitation (PPF) behaviors for the analogous information were mimicked. The temperature dependent PPF behaviors were also investigated systematically. The results indicate that the protonic/electronic hybrid IGZO synaptic transistors would be promising candidates for inorganic synapses in artificial neural network applications.

  3. Fabrication and electrical properties of single wall carbon nanotube channel and graphene electrode based transistors arrays

    International Nuclear Information System (INIS)

    A transistor structure composed of an individual single-walled carbon nanotube (SWNT) channel with a graphene electrode was demonstrated. The integrated arrays of transistor devices were prepared by transferring patterned graphene electrode patterns on top of the aligned SWNT along one direction. Both single and multi layer graphene were used for the electrode materials; typical p-type transistor and Schottky diode behavior were observed, respectively. Based on our fabrication method and device performances, several issues are suggested and discussed to improve the device reliability and finally to realize all carbon based future electronic systems

  4. Paired-pulse facilitation achieved in protonic/electronic hybrid indium gallium zinc oxide synaptic transistors

    International Nuclear Information System (INIS)

    Neuromorphic devices with paired pulse facilitation emulating that of biological synapses are the key to develop artificial neural networks. Here, phosphorus-doped nanogranular SiO2 electrolyte is used as gate dielectric for protonic/electronic hybrid indium gallium zinc oxide (IGZO) synaptic transistor. In such synaptic transistors, protons within the SiO2 electrolyte are deemed as neurotransmitters of biological synapses. Paired-pulse facilitation (PPF) behaviors for the analogous information were mimicked. The temperature dependent PPF behaviors were also investigated systematically. The results indicate that the protonic/electronic hybrid IGZO synaptic transistors would be promising candidates for inorganic synapses in artificial neural network applications

  5. Three-terminal graphene single-electron transistor fabricated using feedback-controlled electroburning

    Science.gov (United States)

    Puczkarski, Paweł; Gehring, Pascal; Lau, Chit S.; Liu, Junjie; Ardavan, Arzhang; Warner, Jamie H.; Briggs, G. Andrew D.; Mol, Jan A.

    2015-09-01

    We report room-temperature Coulomb blockade in a single layer graphene three-terminal single-electron transistor fabricated using feedback-controlled electroburning. The small separation between the side gate electrode and the graphene quantum dot results in a gate coupling up to 3 times larger compared to the value found for the back gate electrode. This allows for an effective tuning between the conductive and Coulomb blocked state using a small side gate voltage of about 1 V. The technique can potentially be used in the future to fabricate all-graphene based room temperature single-electron transistors or three terminal single molecule transistors with enhanced gate coupling.

  6. Paired-pulse facilitation achieved in protonic/electronic hybrid indium gallium zinc oxide synaptic transistors

    Directory of Open Access Journals (Sweden)

    Li Qiang Guo

    2015-08-01

    Full Text Available Neuromorphic devices with paired pulse facilitation emulating that of biological synapses are the key to develop artificial neural networks. Here, phosphorus-doped nanogranular SiO2 electrolyte is used as gate dielectric for protonic/electronic hybrid indium gallium zinc oxide (IGZO synaptic transistor. In such synaptic transistors, protons within the SiO2 electrolyte are deemed as neurotransmitters of biological synapses. Paired-pulse facilitation (PPF behaviors for the analogous information were mimicked. The temperature dependent PPF behaviors were also investigated systematically. The results indicate that the protonic/electronic hybrid IGZO synaptic transistors would be promising candidates for inorganic synapses in artificial neural network applications.

  7. Principles of transistor circuits introduction to the design of amplifiers, receivers and digital circuits

    CERN Document Server

    Amos, S W

    2013-01-01

    For over thirty years, Stan Amos has provided students and practitioners with a text they could rely on to keep them at the forefront of transistor circuit design. This seminal work has now been presented in a clear new format and completely updated to include the latest equipment such as laser diodes, Trapatt diodes, optocouplers and GaAs transistors, and the most recent line output stages and switch-mode power supplies.Although integrated circuits have widespread application, the role of discrete transistors is undiminished, both as important building blocks which students must understand an

  8. Silicide Nanowires for Low-Resistance CMOS Transistor Contacts.

    Science.gov (United States)

    Zollner, Stefan

    2007-03-01

    Transition metal (TM) silicide nanowires are used as contacts for modern CMOS transistors. (Our smallest wires are ˜20 nm thick and ˜50 nm wide.) While much research on thick TM silicides was conducted long ago, materials perform differently at the nanoscale. For example, the usual phase transformation sequences (e.g., Ni, Ni2Si, NiSi, NiSi2) for the reaction of thick metal films on Si no longer apply to nanostructures, because the surface and interface energies compete with the bulk energy of a given crystal structure. Therefore, a NiSi film will agglomerate into hemispherical droplets of NiSi by annealing before it reaches the lowest-energy (NiSi2) crystalline structure. These dynamics can be tuned by addition of impurities (such as Pt in Ni). The Si surface preparation is also a more important factor for nanowires than for silicidation of thick TM films. Ni nanowires formed on Si surfaces that were cleaned and amorphized by sputtering with Ar ions have a tendency to form NiSi2 pyramids (``spikes'') even at moderate temperatures (˜400^oC), while similar Ni films formed on atomically clean or hydrogen-terminated Si form uniform NiSi nanowires. Another issue affecting TM silicides is the barrier height between the silicide contact and the silicon transistor. For most TM silicides, the Fermi level of the silicide is aligned with the center of the Si band gap. Therefore, silicide contacts experience Schottky barrier heights of around 0.5 eV for both n-type and p-type Si. The resulting contact resistance becomes a significant term for the overall resistance of modern CMOS transistors. Lowering this contact resistance is an important goal in CMOS research. New materials are under investigation (for example PtSi, which has a barrier height of only 0.3 eV to p-type Si). This talk will describe recent results, with special emphasis on characterization techniques and electrical testing useful for the development of silicide nanowires for CMOS contacts. In collaboration

  9. Avalanche Ruggedness of Local Charge Balance Power Super Junction Transistors

    OpenAIRE

    Villamor Baliarda, Ana

    2013-01-01

    L'objectiu principal de la Tesi Doctoral és augmentar la fiabilitat dels transistors MOS de potència d'alta capacitat en tensió (600 V) basats en el concepte Super-Unió quan aquests components es sotmeten a les condicions més extremes en convertidors DC/DC i circuits reguladors del factor de potència, on el seu díode intrínsec ha d'absorbir una gran quantitat d'energia en molt poc temps. La Tesi s'ha realitzat en el marc d'una col·laboració entre l'Institut de Microelectrònica de Barcelona (I...

  10. A spin filter transistor made of topological Weyl semimetal

    Science.gov (United States)

    Shi, Zhangsheng; Wang, Maoji; Wu, Jiansheng

    2015-09-01

    Topological boundary states (TBSs) in Weyl semimetal (WSM) thin film can induce tunneling. Such TBSs are spin polarized inducing spin-polarized current, which can be used to build a spin-filter transistor (SFT) in spintronics. The WSM thin film can be viewed as a series of decoupled quantum anomalous Hall insulator (QAHI) wires connected in parallel, so compared with the proposed SFT made of QAHI nanowire, this SFT has a broader working energy region and easier to be manipulated. And within a narrow region outside this energy domain, the 2D WSM is with very low conductance, so it makes a good on/off switch device with controllable chemical potential induced by liquid ion gate. We also construct a loop device made of 2D WSM with inserted controllable flux to control the polarized current.

  11. Adiabatic Charge Control in a Single Donor Atom Transistor

    CERN Document Server

    Prati, Enrico; Cocco, Simone; Petretto, Guido; Fanciulli, Marco

    2010-01-01

    A Silicon quantum device containing a single Arsenic donor and an electrostatic quantum dot in parallel is realized in a nanometric field effect transistor. The different coupling capacitances of the donor and the quantum dot with the control and the back gates determine a relative rigid shift of their energy spectrum as a function of the back gate voltage, causing the crossing of the energy levels. We observe the sequential tunneling through the $D^{2-}$ and the $D^{3-}$ energy levels of the donor at 4.2 K, ordinarily hidden at high temperature as they lie above the conduction band edge of Silicon. The exchange coupling of the localized electrons is controlled in the anticrossing region by moving one electron from the donor to the quantum dot site and \\textit{viceversa}, in order to realize physical qubits for quantum information processing.

  12. Electrospun Polyaniline/Polyethylene Oxide Nanofiber Field Effect Transistor

    Science.gov (United States)

    Pinto, N. J.; Johnson, A. T.; MacDiarmid, A. G.; Mueller, C. H.; Theofylaktos, N.; Robinson, D. C.; Miranda, F. A.

    2003-01-01

    We report on the observation of field effect transistor (FET) behavior in electrospun camphorsulfonic acid doped polyaniline(PANi)/polyethylene oxide(PE0) nanofibers. Saturation channel currents are observed at surprisingly low source/drain voltages. The hole mobility in the depletion regime is 1.4 x 10(exp -4) sq cm/V s while the 1-D charge density (at zero gate bias) is calculated to be approximately 1 hole per 50 two-ring repeat units of polyaniline, consistent with the rather high channel conductivity (approx. 10(exp -3) S/cm). Reducing or eliminating the PEO content in the fiber is expected to enhance device parameters. Electrospinning is thus proposed as a simple method of fabricating 1-D polymer FET's.

  13. Synaptic plasticity functions in an organic electrochemical transistor

    Science.gov (United States)

    Gkoupidenis, Paschalis; Schaefer, Nathan; Strakosas, Xenofon; Fairfield, Jessamyn A.; Malliaras, George G.

    2015-12-01

    Synaptic plasticity functions play a crucial role in the transmission of neural signals in the brain. Short-term plasticity is required for the transmission, encoding, and filtering of the neural signal, whereas long-term plasticity establishes more permanent changes in neural microcircuitry and thus underlies memory and learning. The realization of bioinspired circuits that can actually mimic signal processing in the brain demands the reproduction of both short- and long-term aspects of synaptic plasticity in a single device. Here, we demonstrate the implementation of neuromorphic functions similar to biological memory, such as short- to long-term memory transition, in non-volatile organic electrochemical transistors (OECTs). Depending on the training of the OECT, the device displays either short- or long-term plasticity, therefore, exhibiting non von Neumann characteristics with merged processing and storing functionalities. These results are a first step towards the implementation of organic-based neuromorphic circuits.

  14. Tin - an unlikely ally for silicon field effect transistors?

    KAUST Repository

    Hussain, Aftab M.

    2014-01-13

    We explore the effectiveness of tin (Sn), by alloying it with silicon, to use SiSn as a channel material to extend the performance of silicon based complementary metal oxide semiconductors. Our density functional theory based simulation shows that incorporation of tin reduces the band gap of Si(Sn). We fabricated our device with SiSn channel material using a low cost and scalable thermal diffusion process of tin into silicon. Our high-κ/metal gate based multi-gate-field-effect-transistors using SiSn as channel material show performance enhancement, which is in accordance with the theoretical analysis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Multicolored Nanofiber Based Organic Light-Emitting Transistor

    DEFF Research Database (Denmark)

    With Jensen, Per Baunegaard; Kjelstrup-Hansen, Jakob; Tavares, Luciana;

    For optoelectronic applications, organic semiconductors have several advantages over their inorganic counterparts such as facile synthesis, tunability via synthetic chemistry, and low temperature processing. Self-assembled, molecular crystalline nanofibers are of particular interest as they could...... form ultra-small light-emitters in future nanophotonic applications. Such organic nanofibers exhibit many interesting optical properties including polarized photo- and electroluminescence, waveguiding, and emission color tunability. We here present a first step towards a multicolored, electrically...... driven device by combining nanofibers made from two different molecules, parahexaphenylene (p6P) and 5,5´-Di-4-biphenyl-2,2´-bithiophene (PPTTPP), which emits blue and green light, respectively. The organic nanofibers are implemented on a bottom gate/bottom contact field-effect transistor platform using...

  16. Exploration of vertical scaling limit in carbon nanotube transistors

    Science.gov (United States)

    Qiu, Chenguang; Zhang, Zhiyong; Yang, Yingjun; Xiao, Mengmeng; Ding, Li; Peng, Lian-Mao

    2016-05-01

    Top-gated carbon nanotube field-effect transistors (CNT FETs) were fabricated by using ultra-thin (4.5 nm or thinner) atomic-layer-deposition grown HfO2 as gate insulator, and shown to exhibit high gate efficiency, i.e., all examined (totally 76) devices present very low room temperature subthreshold swing with an averaged value of 64 mV/Dec, without observable carrier mobility degradation. The gate leakage of the CNT FET under fixed gate voltage is dependent not only on the thickness of HfO2 insulator, but also on the diameter of the CNT. The vertical scaling limit of CNT FETs is determined by gate leakage standard in ultra large scale integrated circuits. HfO2 film with effective oxide thickness of 1.2 nm can provide both excellent gate electrostatic controllability and small gate leakage for sub-5 nm FETs based on CNT with small diameter.

  17. MoS{sub 2} nanotube field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Strojnik, M., E-mail: martin.strojnik@ijs.si, E-mail: dragan.mihailovic@ijs.si; Mrzel, A.; Buh, J.; Strle, J. [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Kovic, A. [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Jozef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana (Slovenia); Mihailovic, D., E-mail: martin.strojnik@ijs.si, E-mail: dragan.mihailovic@ijs.si [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Center of excellence in Nanoscience and Nanotechnology, Jamova cesta 39, 1000 Ljubljana (Slovenia)

    2014-09-15

    We report on electric field effects on electron transport in multi-walled MoS{sub 2} nanotubes (NTs), fabricated using a two-step synthesis method from Mo{sub 6}S{sub x}I{sub 9-x} nanowire bundle precursors. Transport properties were measured on 20 single nanotube field effect transistor (FET) devices, and compared with MoS{sub 2} layered crystal devices prepared using identical fabrication techniques. The NTs exhibited mobilities of up to 0.014 cm{sup 2}V{sup −1}s{sup −1} and an on/off ratio of up to 60. As such they are comparable with previously reported WS{sub 2} nanotube FETs, but materials defects and imperfections apparently limit their performance compared with multilayer MoS{sub 2} FETs with similar number of layers.

  18. Resolving ambiguities in nanowire field-effect transistor characterization.

    Science.gov (United States)

    Heedt, Sebastian; Otto, Isabel; Sladek, Kamil; Hardtdegen, Hilde; Schubert, Jürgen; Demarina, Natalia; Lüth, Hans; Grützmacher, Detlev; Schäpers, Thomas

    2015-11-21

    We have modeled InAs nanowires using finite element methods considering the actual device geometry, the semiconducting nature of the channel and surface states, providing a comprehensive picture of charge distribution and gate action. The effective electrostatic gate width and screening effects are taken into account. A pivotal aspect is that the gate coupling to the nanowire is compromised by the concurrent coupling of the gate electrode to the surface/interface states, which provide the vast majority of carriers for undoped nanowires. In conjunction with field-effect transistor (FET) measurements using two gates with distinctly dissimilar couplings, the study reveals the density of surface states that gives rise to a shallow quantum well at the surface. Both gates yield identical results for the electron concentration and mobility only at the actual surface state density. Our method remedies the flaws of conventional FET analysis and provides a straightforward alternative to intricate Hall effect measurements on nanowires. PMID:26482127

  19. MoS2 nanotube field effect transistors

    Directory of Open Access Journals (Sweden)

    M. Strojnik

    2014-09-01

    Full Text Available We report on electric field effects on electron transport in multi-walled MoS2 nanotubes (NTs, fabricated using a two-step synthesis method from Mo6SxI9-x nanowire bundle precursors. Transport properties were measured on 20 single nanotube field effect transistor (FET devices, and compared with MoS2 layered crystal devices prepared using identical fabrication techniques. The NTs exhibited mobilities of up to 0.014 cm2V−1s−1 and an on/off ratio of up to 60. As such they are comparable with previously reported WS2 nanotube FETs, but materials defects and imperfections apparently limit their performance compared with multilayer MoS2 FETs with similar number of layers.

  20. Energy capability enhancement for isolated extended drain NMOS transistors

    Institute of Scientific and Technical Information of China (English)

    聂卫东; 吴金; 马晓辉; 于宗光

    2012-01-01

    Isolated extended drain NMOS (EDNMOS) transistors are widely used in power signal processing.The hole current induced by a high electric field can result in a serious reliability problem due to a parasitic NPN effect.By optimizing p-type epitaxial (p-epi) thickness,n-type buried layer (BLN) and nwell doping distribution,the peak electric field is decreased by 30% and the peak hole current is decreased by 60%,which obviously suppress the parasitic NPN effect.Measured I-V characteristics and transmission line pulsing (TLP) results show that the onstate breakdown voltage is increased from 28 to 37 V when 6 V Vgs is applied and the energy capability is improved by about 30%,while the on-state resistance remains unchanged.