Use of the field effect to determine the energy dependence of localized state density in amorphous semiconductors

1972 ◽  
Vol 10 (11) ◽  
pp. 1081-1083 ◽  
Author(s):  
R.F. Egerton
Keyword(s):  
Energy Dependence ◽  
Field Effect ◽  
State Density ◽  
Amorphous Semiconductors ◽  
Localized State

scholarly journals Epitaxial Growth and Optically Pumped Stimulated Emission in AlGaN/InGaN Ultraviolet Multi-Quantum-Well Structures

2020 ◽  
Vol 49 (4) ◽  
pp. 2326-2331
Author(s):  
Ping Chen ◽  
Young Jae Park ◽  
Yuh-Shiuan Liu ◽  
Theeradetch Detchprohm ◽  
P. Douglas Yoder ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Thermal Effect ◽  
Epitaxial Growth ◽  
Growth Temperature ◽  
Optimal Growth ◽  
State Density ◽  
Stimulated Emission ◽  
Multiple Quantum ◽  
Quantum Well Structures ◽  
Localized State

AbstractThe thermal effect of the growth temperature on interface morphology and stimulated emission in ultraviolet AlGaN/InGaN multiple quantum wells (MQWs) are experimentally investigated. During the MOCVD epitaxial growth of AlGaN/InGaN MQWs, the ramping rate from a lower temperature for InGaN quantum wells (QWs) to a higher one for AlGaN quantum barriers (QBs) is intentionally changed from 1.0°C/s to 4.0°C/s. Atomic force microscopy images show that the surface morphology of InGaN QWs, which is improved by a thermal effect when the growth temperature rises to the set value of the AlGaN QBs, varies with different temperature ramping rates. The results of stimulated emission indicate that the threshold pumping power density of MQWs is decreased with increasing temperature ramping rate from 1.0°C/s to 3.0°C/s and then slightly increased when the ramping rate is 4.0°C/s. This phenomenon is believed to result from the thermal degradation effect during the temperature ramp step. A long-time high-temperature annealing will reduce the density of indium-rich microstructures as well as the corresponding localized state density, which is assumed to contribute to the radiative recombination in the InGaN QWs. Given the great difference between optimal growth temperatures for AlGaN and InGaN layers, a higher ramping rate would be more appropriate for the growth of ultraviolet AlGaN/InGaN MQWs.

The Mobility Lifetime Product of Electrons as a Function of Temperature and Electron Concentrations in a-Si:H

1994 ◽  
Vol 336 ◽  
Author(s):  
Shinichi Nishida ◽  
Hellmut Fritzsche
Keyword(s):  
Cross Sections ◽  
Field Effect ◽  
Thin Film Transistor ◽  
State Density ◽  
Drift Diffusion ◽  
Full Account ◽  
Localization Radius ◽  
Fitting Parameters ◽  
Si Thin Film ◽  
Capture Cross Sections

ABSTRACTThe photo-field effect has been measured between 4.2K and 300K using an a-Si thin film transistor. The data are fit self-consistently taking full account of changes in space charge, photo carrier drift, diffusion and recombination. Gap state density and capture cross sections are fitting parameters. Evidence for tunnel recombination is found. Electron localization radius was found to be 13Å.

A Reduction of Defects in the SiO2-SiC System Using the SiC Vacuum Field-Effect Transistor (VacFET)

2012 ◽  
Vol 717-720 ◽  
pp. 777-780
Author(s):  
Kevin M. Speer ◽  
Philip G. Neudeck ◽  
Mehran Mehregany
Keyword(s):  
Field Effect ◽  
Field Effect Transistor ◽  
Interface State ◽  
State Density ◽  
Vacuum Field ◽  
Semiconductor Surface ◽  
Fundamental Properties ◽  
Voltage Instability ◽  
Effect Transistor ◽  
State Densities

The SiC vacuum field-effect transistor (VacFET) was first reported in 2010 as a diagnostic tool for characterizing the fundamental properties of the inverted SiC semiconductor surface without confounding issues associated with thermal oxidation. In this paper, interface state densities are extracted from measurements of threshold voltage instability on a SiC VacFET and a SiC MOSFET. It is shown that removing the oxide can reduce the interface state density by more than 70%.

Improved Field Effect Mobility in Si-Face 4H-SiC MOSFETs with a Deposited SiNx Interface Layer

2019 ◽  
Vol 963 ◽  
pp. 469-472 ◽  
Author(s):  
Teruaki Kumazawa ◽  
Mitsuo Okamoto ◽  
Miwako Iijima ◽  
Yohei Iwahashi ◽  
Shinji Fujikake ◽  
...  
Keyword(s):  
Field Effect ◽  
Atomic Layer ◽  
Interface Layer ◽  
Interface State ◽  
State Density ◽  
Field Effect Mobility ◽  
Optimal Thickness ◽  
Interface Quality ◽  
Mos Devices ◽  
Layer Deposition

The SiO2/SiC interface quality has a significant effect on the performance of 4H-SiC MOS devices. The introduction of nitrogen to the SiO2/SiC interface is a well-known method for reducing the interface state density (Dit). In this study, we introduced nitrogen to the SiO2/SiC interface by forming SiNx films using atomic layer deposition (ALD) and thus improved the interface quality. O2 annealing with a SiNx interface layer of optimal thickness enhanced the field effect mobility.

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