High Photo-to-Dark-Current Ratio in SiGe/Si Schottky-Barrier Photodetectors by Using an a-Si:H Cap Layer

2007 ◽  
Vol 54 (9) ◽  
pp. 2386-2391 ◽  
Author(s):  
Jun-Dar Hwang ◽  
Y.H. Chen ◽  
C.Y. Kung ◽  
J.C. Liu
Keyword(s):  
Schottky Barrier ◽  
Dark Current ◽  
Current Ratio ◽  
Cap Layer

GaN ON SILICON SUBSTRATE WITH AlN BUFFER LAYER FOR UV PHOTODIODE

2012 ◽  
Vol 21 (01) ◽  
pp. 1250014 ◽  
Author(s):  
L. S. CHUAH ◽  
S. M. THAHAB ◽  
Z. HASSAN
Keyword(s):  
Schottky Barrier ◽  
Buffer Layer ◽  
Barrier Height ◽  
Silicon Substrate ◽  
Dark Current ◽  
Schottky Barrier Height ◽  
Buffer Layers ◽  
Current Ratio ◽  
Principal Mechanism ◽  
Aln Buffer

Nitrogen plasma-assisted molecular beam epitaxy (PAMBE) deposited GaN thin films on (111) n-type silicon substrate with different thickness AlN buffer layers are investigated and distinguished by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and Raman scattering. The thickness of AlN buffer layer ranged from 200 nm to 300 nm. Besides that, the electrical characteristics of the GaN thin film for ultraviolet detecting utilizations are studied by calculating the photo current/dark current ratio on a metal-semiconductor-metal (MSM) photodiode with and without the illumination of Hg-lamp source. The devices have been tested over room temperature (RT). The photocurrent analysis, together with the study of Schottky barrier height (SBH) development, ascertain that the principal mechanism of photo transport is thermionic emission. The photocurrent value is rigorously dependent on Schottky barrier height. The GaN/AlN(200 nm)/n-Si MSM photodiode produces the highest photo/dark current ratio for the lowest strain that consists of the GaN film grown on the AlN (200 nm) buffer layer.

Low dark current quasi-Schottky barrier MSM-photodiode structures onn-Ga0.47In0.53As Withp+-Ga0.47In0.53As cap layer

1992 ◽  
Vol 28 (11) ◽  
pp. 992-995 ◽  
Author(s):  
S.V. Averin ◽  
A. Kohl ◽  
R. Müller ◽  
A. Mesquida Küsters ◽  
J. Wisser ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Dark Current ◽  
Cap Layer

Reduction of Dark Current in AlGaN–GaN Schottky-Barrier Photodetectors With a Low-Temperature-Grown GaN Cap Layer

2004 ◽  
Vol 25 (9) ◽  
pp. 593-595 ◽  
Author(s):  
M.L. Lee ◽  
J.K. Sheu ◽  
Y.K. Su ◽  
S.J. Chang ◽  
W.C. Lai ◽  
...  
Keyword(s):  
Low Temperature ◽  
Schottky Barrier ◽  
Dark Current ◽  
Cap Layer

Reduction of dark current in AlGaN/GaN Schottky barrier photodetectors with a low-temperature-grown GaN cap layer

2003 ◽  
Vol 798 ◽  
Author(s):  
G. C. Chi ◽  
J. K. Sheu ◽  
M. L. Lee ◽  
C. J. Kao ◽  
Y. K. Su ◽  
...  
Keyword(s):  
Low Temperature ◽  
Schottky Barrier ◽  
Leakage Current ◽  
Dark Current ◽  
Reverse Bias ◽  
Incident Light ◽  
Response Speed ◽  
Light Wavelength ◽  
Cap Layer ◽  
Incident Light Wavelength

ABSTRACTAlGaN/GaN-based ultraviolet (UV) Schottky barrier photodetectors (PDs) with and without the LT GaN cap layer were both fabricated. It was found that we could achieve a lower leakage current from sample A. With incident light wavelength of 320 nm and a –1 V reverse bias, the measured responsivity was around 0.03 A/W and 0.015 A/W for samples with and without the LT GaN cap layer, respectively. The response speed of the sample A was also found to be faster.

Monodispersed hierarchical ZnGa2O4 microflowers for self-powered solar-blind detection

2016 ◽  
Vol 4 (15) ◽  
pp. 3113-3118 ◽  
Author(s):  
Yue Teng ◽  
Le Xin Song ◽  
Wei Liu ◽  
Zhe Yuan Xu ◽  
Qing Shan Wang ◽  
...  
Keyword(s):  
Response Time ◽  
Bias Voltage ◽  
Dark Current ◽  
Blind Detection ◽  
Current Ratio ◽  
Zero Bias ◽  
Single Crystalline ◽  
Short Response Time ◽  
Solar Blind ◽  
Self Powered

We successfully synthesized ZnGa2O4 microflowers self-assembled by hexagonal single-crystalline nanopetals. The ZnGa2O4 crystal exhibits improved solar-blind detection performance such as short response time, large light to dark current ratio and high photocurrent stability under zero bias voltage.

ORGANIC CuPc COATING INDUCED IMPROVED PHOTOLUMINESCENCE AND PHOTOCONDUCTIVITY OF ZnO NANOWIRES ARRAY

2012 ◽  
Vol 05 (03) ◽  
pp. 1250021 ◽  
Author(s):  
SOUMEN DHARA ◽  
P. K. GIRI
Keyword(s):  
Charge Transfer ◽  
Dark Current ◽  
Surface Defects ◽  
Green Emission ◽  
Charge Transfer Process ◽  
Current Ratio ◽  
Uv Emission ◽  
Surface Covering ◽  
Interfacial Charge ◽  
Nanowires Array

In this work, we investigated the effect of organic CuPc coating on the surface of the ZnO NWs for possible improvement in the photoluminescence, photoconductivity and photoresponse. As a result of surface covering, the UV emission is enhanced by a factor of 7–8 while the green emission is reduced to half. Despite an increase in dark current after the CuPc covering, we obtained a significant improvement in the photocurrent and photoresponse rate. The photocurrent-to-dark current ratio is nearly doubled and the photoresponse process becomes faster for the ZnO/CuPc heterostructure. Improvements in the photoluminescence and photoconductivity for the ZnO/CuPc heterostructure are explained on the basis of modification of surface defects and interfacial charge transfer process.

Large-size (1.7 × 1.7 mm2) β-Ga2O3 field-plated trench MOS-type Schottky barrier diodes with 1.2 kV breakdown voltage and 109 high on/off current ratio

2021 ◽  
Vol 15 (1) ◽  
pp. 016501
Author(s):  
Fumio Otsuka ◽  
Hironobu Miyamoto ◽  
Akio Takatsuka ◽  
Shinji Kunori ◽  
Kohei Sasaki ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Leakage Current ◽  
Schottky Barrier Diodes ◽  
Wafer Level ◽  
Current Ratio ◽  
Field Plate ◽  
Low Leakage ◽  
Large Size ◽  
Forward Current ◽  
Low Leakage Current

Abstract We fabricated high forward and low leakage current trench MOS-type Schottky barrier diodes (MOSSBDs) in combination with a field plate on a 12 μm thick epitaxial layer grown by halide vapor phase epitaxy on β-Ga2O3 (001) substrate. The MOSSBDs, measuring 1.7 × 1.7 mm2, exhibited a forward current of 2 A (70 A cm−2) at 2 V forward voltage and a leakage current of 5.7 × 10–10 A at −1.2 kV reverse voltage (on/off current ratio of > 109) with an ideality factor of 1.05 and wafer-level specific on-resistance of 17.1 mΩ · cm2.

GaN Schottky barrier photodetectors with a low-temperature GaN cap layer

2003 ◽  
Vol 82 (17) ◽  
pp. 2913-2915 ◽  
Author(s):  
M. L. Lee ◽  
J. K. Sheu ◽  
W. C. Lai ◽  
S. J. Chang ◽  
Y. K. Su ◽  
...  
Keyword(s):  
Low Temperature ◽  
Schottky Barrier ◽  
Cap Layer

Tail-states induced appearance of conductor‑like behaviour in zinc‑tin‑oxide photo‑thinfilm transistors under sub-bandgap light excitation

2021 ◽  
Author(s):  
Soumen Dhara ◽  
Kham Niang ◽  
Andrew Flewitt ◽  
Arokia Nathan ◽  
Stephen Lynch
Keyword(s):  
Tin Oxide ◽  
Dark Current ◽  
Direct Evidence ◽  
Uv Light ◽  
Amorphous Structure ◽  
Persistent Photoconductivity ◽  
Current Analysis ◽  
Current Ratio ◽  
Zinc Tin Oxide ◽  
Light Excitation

Abstract We report on a strong persistent photoconductivity (PPC) induced appearance of conductor‑like behaviour in zinc-tin-oxide (ZTO) photo-thinfilm transistors (TFT). The active ZTO channel layer was prepared by remote-plasma reactive sputtering and possesses an amorphous structure. Under sub-bandgap excitation of ZTO with UV light, the photocurrent reaches as high as ~10-4 A (a photo-to-dark current ratio of ~107) and remains close to this high value after switching off the light. During this time, the ZTO TFT exhibits strong PPC with long-lasting recovery time, which leads the appearance of the conductor‑like behaviour in ZTO semiconductor. In the present case, the conductivity changes over six orders of magnitude, from ~10-7 to 0.92 Ω-1cm-1. After UV exposure, the ZTO compound can potentially remain in the conducting state for up to a month. The underlying physics of the observed PPC effect is investigated by studying defects (deep-states and tail-states) by employing a discharge current analysis (DCA) technique. Findings from the DCA study reveal direct evidence for the involvement of sub-gap tail-states of the ZTO in the strong PPC, while deep-states contribute to mild PPC.

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