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.

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.

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.

Research status of dark current in CMOS image sensor

2021 ◽  
Author(s):  
Lei Yan ◽  
feng shi ◽  
hongchang cheng ◽  
ye yang ◽  
bin ren ◽  
...  
Keyword(s):  
Dark Current ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Research Status

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.

scholarly journals Proximity Gettering Design of Hydrocarbon–Molecular–Ion–Implanted Silicon Wafers Using Dark Current Spectroscopy for CMOS Image Sensors

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2073 ◽  
Author(s):  
Kazunari Kurita ◽  
Takeshi Kadono ◽  
Satoshi Shigematsu ◽  
Ryo Hirose ◽  
Ryosuke Okuyama ◽  
...  
Keyword(s):  
Dark Current ◽  
Image Sensor ◽  
Image Sensors ◽  
Silicon Wafers ◽  
Device Fabrication ◽  
Oxide Semiconductor ◽  
Device Performance ◽  
Molecular Ion ◽  
Cmos Image Sensors ◽  
Ion Implanted

We developed silicon epitaxial wafers with high gettering capability by using hydrocarbon–molecular–ion implantation. These wafers also have the effect of hydrogen passivation on process-induced defects and a barrier to out-diffusion of oxygen of the Czochralski silicon (CZ) substrate bulk during Complementary metal-oxide-semiconductor (CMOS) device fabrication processes. We evaluated the electrical device performance of CMOS image sensor fabricated on this type of wafer by using dark current spectroscopy. We found fewer white spot defects compared with those of intrinsic gettering (IG) silicon wafers. We believe that these hydrocarbon–molecular–ion–implanted silicon epitaxial wafers will improve the device performance of CMOS image sensors.

scholarly journals Phosphorus Versus Arsenic: Role of the Photodiode Doping Element in CMOS Image Sensor Radiation-Induced Dark Current and Random Telegraph Signal

2020 ◽  
Vol 67 (7) ◽  
pp. 1241-1250
Author(s):  
Alexandre Le Roch ◽  
Cedric Virmontois ◽  
Philippe Paillet ◽  
Jean-Marc Belloir ◽  
Serena Rizzolo ◽  
...  
Keyword(s):  
Dark Current ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Random Telegraph Signal ◽  
Doping Element ◽  
Radiation Induced

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
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