scholarly journals Structural Features and Photoelectric Properties of Si-Doped GaAs under Gamma Irradiation

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 340 ◽  
Author(s):  
Ye Shen ◽  
Xuan Fang ◽  
Xiang Ding ◽  
Haiyan Xiao ◽  
Xia Xiang ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Gamma Irradiation ◽  
Wide Band ◽  
Structural Features ◽  
High Electron ◽  
Nonradiative Recombination ◽  
Photoluminescence Intensity ◽  
Light Emitting Devices ◽  
Photoelectric Properties ◽  
Si Doped

GaAs has been demonstrated to be a promising material for manufacturing semiconductor light-emitting devices and integrated circuits. It has been widely used in the field of aerospace, due to its high electron mobility and wide band gap. In this study, the structural and photoelectric characteristics of Si-doped GaAs under different gamma irradiation doses (0, 0.1, 1 and 10 KGy) are investigated. Surface morphology studies show roughen of the surface with irradiation. Appearance of transverse-optical (TO) phonon mode and blueshift of TO peak reflect the presence of internal strain with irradiation. The average strain has been measured to be 0.009 by Raman spectroscopy, indicating that the irradiated zone still has a good crystallinity even at a dose of 10 KGy. Photoluminescence intensity is increased by about 60% under 10 KGy gamma irradiation due to the strain suppression of nonradiative recombination centers. Furthermore, the current of Si-doped GaAs is reduced at 3V bias with the increasing gamma dose. This study demonstrates that the Si-doped GaAs has good radiation resistance under gamma irradiation, and appropriate level of gamma irradiation can be used to enhance the luminescence property of Si-doped GaAs.

scholarly journals Monolithic Si-Based AlGaN/GaN MIS-HEMTs Comparator and Its High Temperature Characteristics

2021 ◽  
Vol 11 (24) ◽  
pp. 12057
Author(s):  
Fan Li ◽  
Ang Li ◽  
Yuhao Zhu ◽  
Chengmurong Ding ◽  
Yubo Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Integrated Circuits ◽  
Wide Band ◽  
High Electron Mobility Transistor ◽  
High Electron ◽  
Static Characteristics ◽  
Wide Band Gap ◽  
Mixed Signal Circuits ◽  
Promising Application ◽  
Recessed Gate

Monolithic GaN High Electron Mobility Transistor (HEMT)-integrated circuits are a promising application of wide band-gap materials. To date, most GaN-based devices behave as NMOS-like transistors. As only NMOS GaN HEMT is currently commercially available, its control circuit requires special design if monolithic integration is desired. This article analyzes the schematics of a GaN-based comparator, and three comparator structures are compared through ADS simulation. The optimal structure with the bootstrapped technique is fabricated based on AlGaN/GaN Metal–Insulator–Semiconductor (MIS) HEMT with the recessed gate method. The comparator has excellent static characteristics when the reference voltage increases from 3 V to 8 V. Dynamic waveforms from 10 kHz to 1 MHz are also obtained. High-temperature tests from 25 °C to 250 °C are applied upon both DC and AC characteristics. The mechanisms of instability issues are explained under dynamic working condition. The results prove that the comparator can be used in the state-of-art mixed-signal circuits, demonstrating the potential for the monolithic all-GaN integrated circuits.

Growth and Characterization of GaAs Single Crystals

MRS Bulletin ◽  
1988 ◽  
Vol 13 (10) ◽  
pp. 36-43 ◽  
Author(s):  
A.S. Jordan ◽  
J.M Parsey
Keyword(s):  
Integrated Circuits ◽  
High Speed ◽  
Field Effect Transistors ◽  
Low Noise ◽  
Bipolar Transistors ◽  
High Electron ◽  
Type Conversion ◽  
Light Emitting ◽  
Microwave Monolithic Integrated Circuits ◽  
Si Doped

From a commercial viewpoint, gallium arsenide (GaAs) is currently the leading member of the III-V compound family. Oriented substrates, cut and polished from single-crystal boules, form the materials foundation for a rapidly maturing technology of high speed and high frequency electronic devices and circuits. The initial thrust of GaAs applications was in high powered lasers and light-emitting diodes (LEDs) fabricated on n-type (Si-doped) GaAs wafers grown by the horizontal Bridgman technique. One of the important benefits of using GaAs is the high electron mobility compared to Si. This property has driven the development of low noise and power field-effect transistors (FETs) for microwave applications. The semi-insulating substrate requirement (>107 Ω-cm) was initially met by chromium doping. Currently, the interest is focused on MMIC (microwave monolithic integrated circuits), MIMIC (millimeter microwave ICs), analog ICs for lightwave transmitters and receivers, and digital ICs. The digital circuits have been realized with ion-implanted FETs, selectively doped heterostructure transistors (SDHTs), and heterostructure bipolar transistors (HBTs). Presently, most of the semi-insulating (SI) material processed by the industry is nominally undoped, and grown by the liquid encapsulated Czochralski (LEC) technique. The SI behavior is attained via a delicate balance of deep EL2 donors and carbon acceptors, avoiding chromium in order to eliminate the anomalous out-diffusion and type-conversion associated with this dopant.GaAs wafers up to 4 inches in diameter, with electrical properties homogenized by whole ingot annealing, are currently available from U.S. domestic and overseas suppliers. However, the overall quality is compromised by the large dislocation densities, varying 104 – 105/cm2.

The study of interfacial reactions of nickel thin films on GaAs

1983 ◽  
Vol 41 ◽  
pp. 156-157
Author(s):  
L.J. Chen ◽  
Y.F. Hsieh
Keyword(s):  
Thin Films ◽  
Integrated Circuits ◽  
Interfacial Reactions ◽  
Metal Contacts ◽  
Nickel Thin Films ◽  
Thin Foils ◽  
The Status ◽  
Si Doped ◽  
Electron Microscopes

One measure of the maturity of a device technology is the ease and reliability of applying contact metallurgy. Compared to metal contact of silicon, the status of GaAs metallization is still at its primitive stage. With the advent of GaAs MESFET and integrated circuits, very stringent requirements were placed on their metal contacts. During the past few years, extensive researches have been conducted in the area of Au-Ge-Ni in order to lower contact resistances and improve uniformity. In this paper, we report the results of TEM study of interfacial reactions between Ni and GaAs as part of the attempt to understand the role of nickel in Au-Ge-Ni contact of GaAs.N-type, Si-doped, (001) oriented GaAs wafers, 15 mil in thickness, were grown by gradient-freeze method. Nickel thin films, 300Å in thickness, were e-gun deposited on GaAs wafers. The samples were then annealed in dry N2 in a 3-zone diffusion furnace at temperatures 200°C - 600°C for 5-180 minutes. Thin foils for TEM examinations were prepared by chemical polishing from the GaA.s side. TEM investigations were performed with JE0L- 100B and JE0L-200CX electron microscopes.

Effects of Gamma Irradiation on Optical Properties of Colloidal Nanocrystals

2007 ◽  
Vol 1038 ◽  
Author(s):  
Nathan J Withers ◽  
Krishnaprasad Sankar ◽  
Brian A. Akins ◽  
Tosifa A. Memon ◽  
Jiangjiang Gu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Gamma Irradiation ◽  
Irradiation Dose ◽  
Nanocrystalline Material ◽  
Light Output ◽  
Colloidal Nanocrystals ◽  
Photoluminescence Intensity ◽  
Photoluminescence Properties ◽  
Material Systems ◽  
Dose Radiation

AbstractThe effects of 137Cs gamma irradiation on photoluminescence properties, such as spectra, light output, and lifetime, of several types of colloidal nanocrystals have been investigated. Irradiation-induced damage testing was performed on CdSe/ZnS, LaF3:Eu, LaF3:Ce, ZnO, and PbI2 nanocrystals synthesized on a Schlenk line using appropriate solvents and precursors. Optical degradation of the nanocrystals was evaluated based on the measured dependence of their photoluminescence intensity on the irradiation dose. Radiation hardness varies significantly between various nanocrystalline material systems.

scholarly journals Porous Silicon Structural Evolution from In-Situ Luminescence and Raman Measurements

1996 ◽  
Vol 431 ◽  
Author(s):  
D. R. Tallant ◽  
M. J. Kelly ◽  
T. R. Guilinger ◽  
R. L. Simpson
Keyword(s):  
Porous Silicon ◽  
Silicon Surface ◽  
Structural Evolution ◽  
Surface Oxidation ◽  
Ethanol Solution ◽  
Nonradiative Recombination ◽  
Photoluminescence Intensity ◽  
Exciton Migration ◽  
Photoluminescence Mechanism

AbstractWe performed in-situ photoluminescence and Raman measurements on an anodized silicon surface in the HF/ethanol solution used for anodization. The porous silicon thereby produced, while resident in HF/ethanol, does not immediately exhibit intense photoluminescence. Intense photoluminescence develops spontaneously in HF/ethanol after 18–24 hours or with replacement of the HF/ethanol with water. These results support a quantum confinement mechanism in which exciton migration to traps and nonradiative recombination dominates the de-excitation pathways until silicon nanocrystals are physically separated and energetically decoupled by hydrofluoric acid etching or surface oxidation. The porous silicon surface, as produced by anodization, shows large differences in photoluminescence intensity and peak wavelength over millimeter distances. Parallel Raman measurements implicate nanometer-size silicon particles in the photoluminescence mechanism.

Wide-band polarization controller for Si photonic integrated circuits

2016 ◽  
Vol 41 (24) ◽  
pp. 5656 ◽  
Author(s):  
P. Velha ◽  
V. Sorianello ◽  
M. V. Preite ◽  
G. De Angelis ◽  
T. Cassese ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Photonic Integrated Circuits ◽  
Wide Band ◽  
Polarization Controller

scholarly journals Low-temperature and ammonia-free epitaxy of GaN/AlGaN/GaN heterostructure

2021 ◽  
Author(s):  
David Maria Tobaldi ◽  
Valentina Triminì ◽  
Arianna Cretì ◽  
Mauro Lomascolo ◽  
Stefano Dicorato ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Chemical Vapour ◽  
High Growth ◽  
Wide Band ◽  
Cost Effective ◽  
Organic Chemical ◽  
High Electron ◽  
High Quality ◽  
Lower Growth ◽  
Green Approach

Wide band gap semiconductors are very attractive because of their broad applications as electronics and optoelectronics materials − GaN-based materials being by far the most promising. For the production of such nitride-based optical and power devices, metal-organic chemical vapour deposition (MOCVD) is routinely used. However, this has disadvantages, such as the large consumption of ammonia gas, and the need for high growth temperature. To go beyond such a limit, in this study we successfully developed a remote plasma assisted MOCVD (RPA-MOCVD) approach for the epitaxial growth of high-quality GaN/AlGaN heterostructures on 4H-SiC substrates. Our RPA-MOCVD has the advantages of lower growth temperature (750 °C) compared to conventional MOCVD route, and the use of a remote N2/H2 plasma instead of ammonia for nitrides growth, generating in situ the NHx (x = 0−3) species needed for the growth. As assessed by structural, morphological, optical and electrical characterisation, the proposed strategy provides an overall cost-effective and green approach for high-quality GaN/AlGaN heteroepitaxy, suitable for high electron mobility transistors (HEMT) technology.

High Temperature Silicon Carbide CMOS Integrated Circuits

2011 ◽  
Vol 679-680 ◽  
pp. 726-729 ◽  
Author(s):  
David T. Clark ◽  
Ewan P. Ramsay ◽  
A.E. Murphy ◽  
Dave A. Smith ◽  
Robin. F. Thompson ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Integrated Circuits ◽  
Band Gap ◽  
High Temperatures ◽  
Wide Band ◽  
Cmos Technology ◽  
Cmos Integrated Circuits ◽  
Wide Band Gap ◽  
Circuit Performance

The wide band-gap of Silicon Carbide (SiC) makes it a material suitable for high temperature integrated circuits [1], potentially operating up to and beyond 450°C. This paper describes the development of a 15V SiC CMOS technology developed to operate at high temperatures, n and p-channel transistor and preliminary circuit performance over temperature achieved in this technology.

scholarly journals Fabrication of Strontium Bismuth Oxides as Novel Battery-Type Electrode Materials for High-Performance Supercapacitors

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yinghui Han ◽  
Le Li ◽  
Yunpeng Liu ◽  
Xue Li ◽  
Xiaohan Qi ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Electrode Materials ◽  
Specific Capacity ◽  
Structural Features ◽  
High Electron ◽  
Strontium Content ◽  
X Ray ◽  
Bismuth Oxides ◽  
Improved Performance

A simple and efficient process method for the preparation of strontium bismuth oxides (SBOs) via an impregnation-calcination method is presented. The synthesized active materials are characterized using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The electrochemical performance of the as-synthesized SBO samples is observed to decrease gradually as the strontium content is increased from 25% to 50%. The SBO sample with a Sr/Bi ratio of 1 : 3 shows the highest specific capacitance of 1228.7 F g−1 (specific capacity of 204.8 mAh g−1) at a current density of 1 A g−1 and a good cycling stability (75.1%) over 3000 charge-discharge cycles. The improved performance of the supercapacitors can be attributed to the unique structural features resulting from the addition of appropriate portions of Sr, which supports high electron conductivity and rapid ion/electron transport within the electrode and at the electrode/electrolyte interface. All the results show that the SBOs have considerable potential for use as high-performance battery-type electrodes in supercapacitors.

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