GZO/Si Photodiodes Exhibiting High Photocurrent-to-Dark-Current Ratio

2019 ◽  
Vol 66 (5) ◽  
pp. 2238-2242 ◽  
Author(s):  
Nur Efsan Koksal ◽  
Mohamed Sbeta ◽  
Abdullah Yildiz
Keyword(s):  
Dark Current ◽  
Current Ratio

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.

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.

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.

Amorphous Si:H Heterojunction Photodiode and its Application to a Compact Scanner

1985 ◽  
Vol 49 ◽  
Author(s):  
S. Kaneko ◽  
Y. Kajiwara ◽  
F. Okumura ◽  
T. Ohkubo
Keyword(s):  
Optical System ◽  
Dark Current ◽  
System Performance ◽  
Metal Structure ◽  
Image Sensor ◽  
Metal Contact ◽  
Performance Tests ◽  
Current Ratio ◽  
Photodiode Array

AbstractThis paper reports heterojunction photodiode properties and its application to a compact scanner. The photodiode has ITO / p-a-SiC:H / a-Si:H / metal structure. This diode has high photo to dark current ratio and small photocurrent saturation voltage, because of the excellent blocking characteristics for a heterojunction with large built in potential. Moreover, a-Si:H / metal contact has been investigated. A contact linear image sensor has been fabricated using the heterojunction photodiode array and compact optical system. Performance tests showed excellent results. Good reproduced images have been obtained.

scholarly journals High-Quality AlxGa1−xN Using Low Temperature-Interlayer and its Application to UV Detector

2000 ◽  
Vol 5 (S1) ◽  
pp. 42-48
Author(s):  
M. Iwaya ◽  
S. Terao ◽  
N. Hayashi ◽  
T. Kashima ◽  
T. Detchprohm ◽  
...  
Keyword(s):  
Low Temperature ◽  
Tensile Stress ◽  
Dark Current ◽  
Uv Detector ◽  
High Quality ◽  
Current Ratio ◽  
Uv Photodetectors

Low-temperature (LT-) AlN interlayer reduces tensile stress during growth of AlxGa1−xN, while simultaneously acts as the dislocation filter, especially for dislocations of which Burger’s vector contains [0001] components. UV photodetectors using thus-grown high quality AlxGa1−xN layers were fabricated. The dark current bellow 50 fA at 10 V bias for 10 μm strip allowing a photocurrent to dark current ratio greater than one even at 40 nW/cm2 have been achieved.

Amorphous Silicon Linear Image Sensor

1985 ◽  
Vol 49 ◽  
Author(s):  
T. Ozawa ◽  
M. Takenouchi ◽  
S. Tomiyama
Keyword(s):  
Amorphous Silicon ◽  
Dark Current ◽  
Light Sensitivity ◽  
Image Sensor ◽  
Current Ratio

AbstractDocument width linear image sensor arouse strong and wide interest as a compact image reading component for facsimile and other document readers. Among those, a-Si:H is excellent in stability and light sensitivity. The photosensing element of those sensors have a sandwich-like structure which consist of Cr/i-a-Si:H/ITO. In this structure, i-a-Si:H/ITO shows good shottky contact resulting high photo to dark current ratio and fast photoresponse. We have been developing linear image sensor of A4 and B4 size with resolutions of 8dot/mm and l6dot/mm and had applied successfully to facsimile and image input terminals.

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