Influence of Transparent Electrodes on Image Sensor Performance

1985 ◽  
Vol 49 ◽  
Author(s):  
K. Kempter ◽  
H. Wieczrek ◽  
M. Hoheisel
Keyword(s):  
Response Times ◽  
Image Sensor ◽  
Image Sensors ◽  
Transparent Electrodes ◽  
Sensor Performance ◽  
Decay Times ◽  
Sensor Cell ◽  
Photocurrent Decay

AbstractThe short response times required for image sensors demand blocking contacts at the sensor cell. It was found that the junctions between transparent electrodes (ITO or a thin palladium film) and the metallic back electrode with a-Si:H form blocking contacts yielding photocurrent decay times of the order of some microseconds. The two different time regimes observed for the decay are interpreted as being limited by the drift and the release of holes respectively.

scholarly journals 1/f Noise Modelling and Characterization for CMOS Quanta Image Sensors

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5459
Author(s):  
Wei Deng ◽  
Eric R. Fossum
Keyword(s):  
Analog Circuits ◽  
Image Sensor ◽  
Image Sensors ◽  
Correlated Double Sampling ◽  
Cmos Image Sensors ◽  
Source Follower ◽  
Cmos Analog Circuits ◽  
Different Origins ◽  
Noise Models ◽  
Fitting Model

This work fits the measured in-pixel source-follower noise in a CMOS Quanta Image Sensor (QIS) prototype chip using physics-based 1/f noise models, rather than the widely-used fitting model for analog designers. This paper discusses the different origins of 1/f noise in QIS devices and includes correlated double sampling (CDS). The modelling results based on the Hooge mobility fluctuation, which uses one adjustable parameter, match the experimental measurements, including the variation in noise from room temperature to –70 °C. This work provides useful information for the implementation of QIS in scientific applications and suggests that even lower read noise is attainable by further cooling and may be applicable to other CMOS analog circuits and CMOS image sensors.

scholarly journals Development of Obstacle Recognition System of Humanoids Using Relative Disparity Maps from Small Range Image Sensors

2007 ◽  
Vol 19 (3) ◽  
pp. 290-297
Author(s):  
Naotaka Hikosaka ◽  
◽  
Kei Watanabe ◽  
Kazunori Umeda
Keyword(s):  
Recognition System ◽  
Image Sensor ◽  
Image Sensors ◽  
Easy Plane ◽  
Reference Plane ◽  
Small Range ◽  
Range Image ◽  
Disparity Maps ◽  
Integrated Controller

We discuss the recognition of obstacles by detecting a plane using relative disparity maps obtained from a small range image sensor incorporated in a humanoid. Our proposal enables easy plane detection and obstacle recognition using relative disparity from a reference plane alone. We built an integrated controller that feeds back obstacle information to the humanoid. We confirmed through experiments that the humanoid recognized obstacles and autonomously stopped walking.

scholarly journals Solar-blind ultraviolet photodetector based on graphene/vertical Ga2O3 nanowire array heterojunction

Nanophotonics ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 1557-1562 ◽  
Author(s):  
Tao He ◽  
Yukun Zhao ◽  
Xiaodong Zhang ◽  
Wenkui Lin ◽  
Kai Fu ◽  
...  
Keyword(s):  
Response Times ◽  
Nanowire Array ◽  
Graphene Film ◽  
Fast Response ◽  
Nanowire Arrays ◽  
Monolayer Graphene ◽  
Ultraviolet Photodetector ◽  
Solar Blind ◽  
Decay Times ◽  
First Time

AbstractIn this paper, a solar-blind ultraviolet photodetector (PD) based on the graphene/vertical Ga2O3 nanowire array heterojunction was proposed and demonstrated. To the best of our knowledge, it is the first time that vertical Ga2O3 nanowire arrays have been realized. Ga2O3 nanowires were obtained by thermally oxidizing GaN nanowires grown by molecular beam epitaxy on n-doped Si substrate. Then, a monolayer graphene film was transferred to Ga2O3 nanowires to form the graphene/vertical Ga2O3 nanowire array heterojunction and transparent electrodes. The fabricated device exhibited a responsivity (R) of 0.185 A/W and rejection ratio (R258 nm/R365 nm) of 3×104 at the bias of −5 V. Moreover, the fast response times of this PD were 9 and 8 ms for the rise and decay times under 254 nm illumination, respectively, which are attributed to the unique properties of nanowire arrays and the graphene/vertical Ga2O3 nanowire array heterojunction structure.

Degradation mechanism of star sensor performance caused by radiation damage of CMOS image sensor

2020 ◽  
Vol 49 (5) ◽  
pp. 20190555
Author(s):  
冯婕 Jie Feng ◽  
李豫东 Yudong Li ◽  
文林 Lin Wen ◽  
郭旗 Qi Guo
Keyword(s):  
Radiation Damage ◽  
Degradation Mechanism ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Star Sensor ◽  
Sensor Performance

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 Super Field-of-View Lensless Camera by Coded Image Sensors

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1329 ◽  
Author(s):  
Tomoya Nakamura ◽  
Keiichiro Kagawa ◽  
Shiho Torashima ◽  
Masahiro Yamaguchi
Keyword(s):  
Imaging System ◽  
Complementary Metal Oxide Semiconductor ◽  
Image Sensor ◽  
Image Sensors ◽  
Computational Imaging ◽  
Field Of View ◽  
Oxide Semiconductor ◽  
Back Side ◽  
Cmos Image Sensors ◽  
Rich Information

A lensless camera is an ultra-thin computational-imaging system. Existing lensless cameras are based on the axial arrangement of an image sensor and a coding mask, and therefore, the back side of the image sensor cannot be captured. In this paper, we propose a lensless camera with a novel design that can capture the front and back sides simultaneously. The proposed camera is composed of multiple coded image sensors, which are complementary-metal-oxide-semiconductor (CMOS) image sensors in which air holes are randomly made at some pixels by drilling processing. When the sensors are placed facing each other, the object-side sensor works as a coding mask and the other works as a sparsified image sensor. The captured image is a sparse coded image, which can be decoded computationally by using compressive sensing-based image reconstruction. We verified the feasibility of the proposed lensless camera by simulations and experiments. The proposed thin lensless camera realized super-field-of-view imaging without lenses or coding masks and therefore can be used for rich information sensing in confined spaces. This work also suggests a new direction in the design of CMOS image sensors in the era of computational imaging.

A 4-tap global shutter pixel with enhanced IR sensitivity for VGA time-of-flight CMOS image sensors

2020 ◽  
Vol 2020 (7) ◽  
pp. 103-1-103-6
Author(s):  
Taesub Jung ◽  
Yonghun Kwon ◽  
Sungyoung Seo ◽  
Min-Sun Keel ◽  
Changkeun Lee ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Light Sensitivity ◽  
Image Sensor ◽  
Image Sensors ◽  
Double Sampling ◽  
Back Side ◽  
Long Distance ◽  
Correlated Double Sampling ◽  
Cmos Image Sensors ◽  
Side Illumination

An indirect time-of-flight (ToF) CMOS image sensor has been designed with 4-tap 7 μm global shutter pixel in back-side illumination process. 15000 e- of high full-well capacity (FWC) per a tap of 3.5 μm pitch and 3.6 e- of read-noise has been realized by employing true correlated double sampling (CDS) structure with storage gates (SGs). Noble characteristics such as 86 % of demodulation contrast (DC) at 100MHz operation, 37 % of higher quantum efficiency (QE) and lower parasitic light sensitivity (PLS) at 940 nm have been achieved. As a result, the proposed ToF sensor shows depth noise less than 0.3 % with 940 nm illuminator in even long distance.

A Novel Segment-Based Data Transfer Scheme for Low-Power CMOS Surveillance Image Sensors

2017 ◽  
Vol 27 (02) ◽  
pp. 1850027
Author(s):  
Mehdi Habibi ◽  
Khatereh Akbari ◽  
Marzieh Mokhtari ◽  
Peyman Moallem
Keyword(s):  
Data Transfer ◽  
Cmos Technology ◽  
Image Sensor ◽  
Data Rate ◽  
Image Sensors ◽  
Solar Panels ◽  
Transfer Scheme ◽  
Data Rates ◽  
Low Power Cmos ◽  
The Given

Smart image sensors with low data rate output are well fitted for security and surveillance tasks, since at lower data rates, power consumption is reduced and the image sensor can be operated with limited energy resources such as solar panels. In this paper, a new data transfer scheme is presented to reduce the data rate of the pixels which have undergone value change. Although different pixel difference detecting architectures have been previously reported but it is shown that the given method is more effective in terms of power dissipation and data transfer rate reduction. The proposed architecture is evaluated as a [Formula: see text]-pixel sensor in a standard CMOS technology and comparison with other data transfer approaches is performed in the same process and configuration.

Completely Integrated Contact-Type a-Si/a-SiC Heterojunction Image Sensor with Poly-Si TFT Drivers

1989 ◽  
Vol 149 ◽  
Author(s):  
Hajime Kurihara ◽  
Tetsuyoshi Takeshita ◽  
Shinji Morozumi
Keyword(s):  
Carrier Mobility ◽  
Type A ◽  
Scanning Speed ◽  
Image Sensor ◽  
Image Sensors ◽  
Contact Type ◽  
High Carrier Mobility ◽  
High Carrier ◽  
And Performance

ABSTRACTThis paper describes the performance of both an 8 dots/mm and a 400 DPI contact-type linear image sensors which integrate poly-Si TFT scanning circuits and a-Si/a-SiC heterojunction photodiodes on the same substrate. Each of these image sensors provides excellent cost and performance for their applications. In particular, the 400 DPI image sensor has achieved a higher scanning speed of 1 msec/line by using the integrated scanning circuits with hydrogenated poly-Si TFTs having high carrier mobility.

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