scholarly journals Utilization of Photoconductive Gain in a-Si:H Devices for Radiation Detection

1995 ◽  
Vol 377 ◽  
Author(s):  
H. K. Lee ◽  
J. S. Drewery ◽  
W. S. Hone ◽  
T. Jing ◽  
S. N. Kaplan ◽  
...  
Keyword(s):  
Dark Current ◽  
Radiation Detection ◽  
Current Level ◽  
Current Gain ◽  
Applied Bias ◽  
Device Structure ◽  
Short Pulses ◽  
X Ray ◽  
Photoconductive Gain ◽  
Energetic Charged Particle

ABSTRACTThe photoconductive gain mechanism in a-Si:H was investigated in connection with applications to radiation detection. Various device types such as p-i-n, n-i-n and n-i-p-i-n structures were fabricated and tested. Photoconductive gain was measured in two time scales: one for short pulses of visible light (< 1 μsec) which simulates the transit of an energetic charged particle, and the other for rather long pulses of light (1 msec) which simulates x-ray exposure in medical imaging. We used two definitions of photoconductive gain: current gain and charge gain which is an integration of the current gain. We found typical charge gains of 3 ∼ 9 for short pulses and a few hundred for long pulses at a dark current level of 10 mA/cm2. Various gain results are discussed in terms of the device structure, applied bias and dark current.

Non-Destructive Measurements of III-V Semiconductor Device Structure by a Hard X-ray Microprobe

1991 ◽  
Vol 240 ◽  
Author(s):  
F. Uchida ◽  
J. Shigeta ◽  
Y. SUZUKI
Keyword(s):  
Semiconductor Device ◽  
Film Structure ◽  
Device Structure ◽  
X Ray ◽  
Model Sample ◽  
Device Structures ◽  
The Difference ◽  
X Ray Absorption ◽  
Non Destructive ◽  
Non Destructive Characterization

ABSTRACTA non-destructive characterization technique featuring a hard X-ray Microprobe is demonstrated for lll-V semiconductor device structures. A GaAs FET with a 2 μm gate length is measured as a model sample of a thin film structure. X-ray scanning microscopic images of the FET are obtained by diffracted X-ray and fluorescence X-ray detection. Diffracted X-ray detection measures the difference in gate material and source or drain material as a gray level difference on the image due to the X-ray absorption ratio. Ni Ka fluorescence detection, on the other hand, provides imaging of 500 Å thick Ni layers, which are contained only in the source and drain metals, through non-destructive observation.

Prevention of InP/InGaAs/InP Double Heterojunction Bipolar Transistors from Current Gain Reduction during Passivation

2004 ◽  
Vol 833 ◽  
Author(s):  
Byoung-Gue Min ◽  
Jong-Min Lee ◽  
Seong-Il Kim ◽  
Chul-Won Ju ◽  
Kyung-Ho Lee
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Silicon Oxide ◽  
Surface Recombination ◽  
Surface States ◽  
Bipolar Transistors ◽  
Base Layer ◽  
Current Gain ◽  
Device Structure ◽  
Double Heterojunction ◽  
Gain Reduction

ABSTRACTA significant degradation of current gain of InP/InGaAs/InP double heterojunction bipolar transistors was observed after passivation. The amount of degradation depended on the degree of surface exposure of the p-type InGaAs base layer according to the epi-structure and device structure. The deposition conditions such as deposition temperature, kinds of materials (silicon oxide, silicon nitride and aluminum oxide) and film thickness were not major variables to affect the device performance. The gain reduction was prevented by the BOE treatment before the passivation. A possible explanation of this behavior is that unstable non-stoichiometric surface states produced by excess In, Ga, or As after mesa etching are eliminated by BOE treatment and reduce the surface recombination sites.

scholarly journals Low Dark-Current, High Current-Gain of PVK/ZnO Nanoparticles Composite-Based UV Photodetector by PN-Heterojunction Control

Sensors ◽  
2016 ◽  
Vol 16 (1) ◽  
pp. 74 ◽  
Author(s):  
Sang-Won Lee ◽  
Seung-Hwan Cha ◽  
Kyung-Jae Choi ◽  
Byoung-Ho Kang ◽  
Jae-Sung Lee ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Dark Current ◽  
Current Gain ◽  
High Current ◽  
Uv Photodetector

Electronic Impact of Inclusions in Diamond

2009 ◽  
Vol 1203 ◽  
Author(s):  
Erik M. Muller ◽  
John Smedley ◽  
Balaji Raghothamachar ◽  
Mengjia Gaowei ◽  
Jeffrey W. Keister ◽  
...  
Keyword(s):  
Charge Trapping ◽  
Secondary Phase ◽  
Surface Region ◽  
Phase Region ◽  
Electron Trapping ◽  
Near Surface ◽  
X Ray ◽  
Photoconductive Gain ◽  
Single Crystal Diamond ◽  
Topography Data

AbstractX-ray topography data are compared with photodiode responsivity maps to identify potential candidates for electron trapping in high purity, single crystal diamond. X-ray topography data reveal the defects that exist in the diamond material, which are dominated by non-electrically active linear dislocations. However, many diamonds also contain defects configurations (groups of threading dislocations originating from a secondary phase region or inclusion) in the bulk of the wafer which map well to regions of photoconductive gain, indicating that these inclusions are a source of electron trapping which affect the performance of diamond X-ray detectors. It was determined that photoconductive gain is only possible with the combination of an injecting contact and charge trapping in the near surface region. Typical photoconductive gain regions are 0.2 mm across; away from these near-surface inclusions the device yields the expected diode responsivity.

Investigation on Chromium and PEDOT-PSS Electrodes on CH3NH3PbBr3 Single Crystals: Impact on Dark Current and X-ray Photocurrent

2019 ◽  
Author(s):  
Eric Gros-Daillon ◽  
Jean-Marie Verilhac ◽  
Oriane Baussens ◽  
Smail Amari ◽  
Julien Zaccaro ◽  
...  
Keyword(s):  
Single Crystals ◽  
Dark Current ◽  
X Ray

Morphology and I-V Characteristics of Electrochemically Deposited Zinc Oxide on Silicon

2021 ◽  
Vol 20 (3) ◽  
pp. 32-36
Author(s):  
Ahmad Bukhairi Md Rashid ◽  
Mastura Shafinaz Zainal Abidin ◽  
Shaharin Fadzli Abd Rahman ◽  
Amirjan Nawabjan
Keyword(s):  
Zinc Oxide ◽  
Electrochemical Deposition ◽  
Dark Current ◽  
Room Temperature ◽  
Volume Ratio ◽  
Deposition Process ◽  
X Ray ◽  
Current Voltage ◽  
Electrochemically Deposited ◽  
A Current

This paper reported on the electrochemical deposition of zinc oxide (ZnO) on p-silicon (p-Si) (100) substrate in the mixture of 0.1 M of zinc chloride (ZnCl2) and potassium chloride (KCl) electrolyte at a volume ratio of 1:1, 3:1 and 5:1 namely Sample A, B and C. The deposition process was done in room temperature with a current density of 10 mA/cm2 for 30 minutes. Prior to the experiment, all samples were treated by RCA cleaning steps. All samples were characterized using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The results show that all samples have the same morphology of a flake-like structure with different Zn:O ratio that were 2.81, 2.35 and 2.49 for samples A, B and C. The current-voltage (I-V) characteristic graph was obtained by dark current measurement using Keithley SMU 2400 and the threshold voltage (Vth) values were determined at 2.21 V, 0.85 V and 1.22 V for sample A, B and C respectively which correspond with the Zn:O ratio where the highest value of Zn:O ratio can be found in sample A and the lowest in sample B. Based on these results, it shows that electrochemical deposition technique is capable of being used to deposit the flake-like structure ZnO on semiconductor material to form the p-n junction which behaves like a diode. The value of Vth seems to be depended on the ratio between Zn and O. Higher ratio of Zn and O will cause the higher value of intrinsic carrier concentration and built in potential which will increase the Vth value.

scholarly journals Random Telegraph Noises from the Source Follower, the Photodiode Dark Current, and the Gate-Induced Sense Node Leakage in CMOS Image Sensors

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5447
Author(s):  
Calvin Yi-Ping Chao ◽  
Shang-Fu Yeh ◽  
Meng-Hsu Wu ◽  
Kuo-Yu Chou ◽  
Honyih Tu ◽  
...  
Keyword(s):  
Dark Current ◽  
Image Sensors ◽  
Integration Time ◽  
X Ray ◽  
Multiple Sampling ◽  
Cmos Image Sensors ◽  
Measurement Results ◽  
Source Follower ◽  
Different Types ◽  
Dark Signal

In this paper we present a systematic approach to sort out different types of random telegraph noises (RTN) in CMOS image sensors (CIS) by examining their dependencies on the transfer gate off-voltage, the reset gate off-voltage, the photodiode integration time, and the sense node charge retention time. Besides the well-known source follower RTN, we have identified the RTN caused by varying photodiode dark current, transfer-gate and reset-gate induced sense node leakage. These four types of RTN and the dark signal shot noises dominate the noise distribution tails of CIS and non-CIS chips under test, either with or without X-ray irradiation. The effect of correlated multiple sampling (CMS) on noise reduction is studied and a theoretical model is developed to account for the measurement results.

Photoconductive gain under low-flux X-ray irradiation in 4HCB organic single crystal detectors

2020 ◽  
Vol 13 (7) ◽  
pp. 071004
Author(s):  
Dou Zhao ◽  
Xin Liu ◽  
Jingyi Yu ◽  
Meng Xu ◽  
Binbin Zhang ◽  
...  
Keyword(s):  
Single Crystal ◽  
X Ray ◽  
Photoconductive Gain ◽  
Organic Single Crystal
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