A Novel α-Si(C):H Color Sensor Array

1994 ◽  
Vol 336 ◽  
Author(s):  
Q. Zhu ◽  
H. Stiebig ◽  
P. Rieve ◽  
H. Fischer ◽  
M. Böhm

ABSTRACTA novel α-Si(C):H color sensor array has been developed. In this device a single pixel consists of a combination of an amorphous silicon nipin detector and a crystalline operational amplifier. Steady state and transient opto electronic behavior of the nipin structure have been studied in order to optimize the design of the image sensor. Nipin structures are found to exhibit excellent dynamic range (125 dB) and linearity. The crystalline electronics causes only very little signal distortion which makes this sensor device a potential candidate for color image capture and processing for a wide range of illumination levels.

2018 ◽  
Vol 27 (5) ◽  
pp. 2229-2241 ◽  
Author(s):  
Jiachao Zhang ◽  
Jie Jia ◽  
Andong Sheng ◽  
Keigo Hirakawa

2001 ◽  
Vol 664 ◽  
Author(s):  
F. Lemmi ◽  
M. Mulato ◽  
J. Ho ◽  
R. Lau ◽  
J. P. Lu ◽  
...  

ABSTRACTThis paper reports on the first full realization and characterization of a two-dimensional array of amorphous silicon (a-Si:H) color sensors, addressed by integrated amorphous silicon-based thin-film transistors (TFTs). The array includes 512 × 512 pixels with 75-µm pitch, or about 340 dpi. Each pixel features a color sensor realized by a p-i-n-i-p stack of doped and undoped a-Si:H layers, and the TFT. The color sensors are made of two back-to-back p-i-n diodes, which selectively sense the illumination according to the polarity of the applied bias voltage. The sensor layers are grown on top of the TFTs to improve the array fill factor. The p-in-i-p sensor stack is mesa-isolated into single sensors to reduce cross-talk.Images are acquired using two bias voltages and yield the red and blue/green components of the original with a good color separation. A color image is reconstructed using the information from the two images acquired. Aside from a color bias, which is expected for a two-color reconstruction, the imaging system works well. In particular, the array shows very low leakage currents, which enable a very large dynamic range and sensitivity. In the response of the array to a light pulse, the bottom thick diode ensures a fast drop in the signal after the flash, while the top thin diode exhibits some residual image lag.


2013 ◽  
Vol 60 (8) ◽  
pp. 2116-2129 ◽  
Author(s):  
Derek Ho ◽  
Noor ◽  
Krull ◽  
Glenn Gulak ◽  
Roman Genov

1994 ◽  
Vol 336 ◽  
Author(s):  
H. Fischer ◽  
J. Schulte ◽  
P. Rieve ◽  
M. Böhm

ABSTRACTA TFA image sensor consists of an amorphous silicon based multilayer structure on top of a crystalline ASIC. The Multilayer acts as the optical detector, whereas the ASIC performs analog or digital signal processing for each individual pixel. Depending on the operation Mode, the dynamic range of the detector exceeds the performance of conventional CCDs by far. Pixel electronics which is adapted to the requirements of the detector can thereby maximize the dynamic range of the complete sensor array. Crosstalk among adjacent pixels can be eliminated by technological or electronic Means.


2020 ◽  
Vol 2020 (7) ◽  
pp. 143-1-143-6 ◽  
Author(s):  
Yasuyuki Fujihara ◽  
Maasa Murata ◽  
Shota Nakayama ◽  
Rihito Kuroda ◽  
Shigetoshi Sugawa

This paper presents a prototype linear response single exposure CMOS image sensor with two-stage lateral overflow integration trench capacitors (LOFITreCs) exhibiting over 120dB dynamic range with 11.4Me- full well capacity (FWC) and maximum signal-to-noise ratio (SNR) of 70dB. The measured SNR at all switching points were over 35dB thanks to the proposed two-stage LOFITreCs.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ibtissame Khaoua ◽  
Guillaume Graciani ◽  
Andrey Kim ◽  
François Amblard

AbstractFor a wide range of purposes, one faces the challenge to detect light from extremely faint and spatially extended sources. In such cases, detector noises dominate over the photon noise of the source, and quantum detectors in photon counting mode are generally the best option. Here, we combine a statistical model with an in-depth analysis of detector noises and calibration experiments, and we show that visible light can be detected with an electron-multiplying charge-coupled devices (EM-CCD) with a signal-to-noise ratio (SNR) of 3 for fluxes less than $$30\,{\text{photon}}\,{\text{s}}^{ - 1} \,{\text{cm}}^{ - 2}$$ 30 photon s - 1 cm - 2 . For green photons, this corresponds to 12 aW $${\text{cm}}^{ - 2}$$ cm - 2 ≈ $$9{ } \times 10^{ - 11}$$ 9 × 10 - 11 lux, i.e. 15 orders of magnitude less than typical daylight. The strong nonlinearity of the SNR with the sampling time leads to a dynamic range of detection of 4 orders of magnitude. To detect possibly varying light fluxes, we operate in conditions of maximal detectivity $${\mathcal{D}}$$ D rather than maximal SNR. Given the quantum efficiency $$QE\left( \lambda \right)$$ Q E λ of the detector, we find $${ \mathcal{D}} = 0.015\,{\text{photon}}^{ - 1} \,{\text{s}}^{1/2} \,{\text{cm}}$$ D = 0.015 photon - 1 s 1 / 2 cm , and a non-negligible sensitivity to blackbody radiation for T > 50 °C. This work should help design highly sensitive luminescence detection methods and develop experiments to explore dynamic phenomena involving ultra-weak luminescence in biology, chemistry, and material sciences.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2506
Author(s):  
Nguyen Hoai Ngo ◽  
Kazuhiro Shimonomura ◽  
Taeko Ando ◽  
Takayoshi Shimura ◽  
Heiji Watanabe ◽  
...  

A burst image sensor named Hanabi, meaning fireworks in Japanese, includes a branching CCD and multiple CMOS readout circuits. The sensor is backside-illuminated with a light/charge guide pipe to minimize the temporal resolution by suppressing the horizontal motion of signal carriers. On the front side, the pixel has a guide gate at the center, branching to six first-branching gates, each bifurcating to second-branching gates, and finally connected to 12 (=6×2) floating diffusions. The signals are either read out after an image capture operation to replay 12 to 48 consecutive images, or continuously transferred to a memory chip stacked on the front side of the sensor chip and converted to digital signals. A CCD burst image sensor enables a noiseless signal transfer from a photodiode to the in-situ storage even at very high frame rates. However, the pixel count conflicts with the frame count due to the large pixel size for the relatively large in-pixel CCD memory elements. A CMOS burst image sensor can use small trench-type capacitors for memory elements, instead of CCD channels. However, the transfer noise from a floating diffusion to the memory element increases in proportion to the square root of the frame rate. The Hanabi chip overcomes the compromise between these pros and cons.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ze Peng ◽  
Yanhong He ◽  
Saroj Parajuli ◽  
Qian You ◽  
Weining Wang ◽  
...  

AbstractDowny mildew (DM), caused by obligate parasitic oomycetes, is a destructive disease for a wide range of crops worldwide. Recent outbreaks of impatiens downy mildew (IDM) in many countries have caused huge economic losses. A system to reveal plant–pathogen interactions in the early stage of infection and quickly assess resistance/susceptibility of plants to DM is desired. In this study, we established an early and rapid system to achieve these goals using impatiens as a model. Thirty-two cultivars of Impatiens walleriana and I. hawkeri were evaluated for their responses to IDM at cotyledon, first/second pair of true leaf, and mature plant stages. All I. walleriana cultivars were highly susceptible to IDM. While all I. hawkeri cultivars were resistant to IDM starting at the first true leaf stage, many (14/16) were susceptible to IDM at the cotyledon stage. Two cultivars showed resistance even at the cotyledon stage. Histological characterization showed that the resistance mechanism of the I. hawkeri cultivars resembles that in grapevine and type II resistance in sunflower. By integrating full-length transcriptome sequencing (Iso-Seq) and RNA-Seq, we constructed the first reference transcriptome for Impatiens comprised of 48,758 sequences with an N50 length of 2060 bp. Comparative transcriptome and qRT-PCR analyses revealed strong candidate genes for IDM resistance, including three resistance genes orthologous to the sunflower gene RGC203, a potential candidate associated with DM resistance. Our approach of integrating early disease-resistance phenotyping, histological characterization, and transcriptome analysis lay a solid foundation to improve DM resistance in impatiens and may provide a model for other crops.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Raju Bheemanahalli ◽  
Montana Knight ◽  
Cherryl Quinones ◽  
Colleen J. Doherty ◽  
S. V. Krishna Jagadish

AbstractHigh night temperatures (HNT) are shown to significantly reduce rice (Oryza sativa L.) yield and quality. A better understanding of the genetic architecture of HNT tolerance will help rice breeders to develop varieties adapted to future warmer climates. In this study, a diverse indica rice panel displayed a wide range of phenotypic variability in yield and quality traits under control night (24 °C) and higher night (29 °C) temperatures. Genome-wide association analysis revealed 38 genetic loci associated across treatments (18 for control and 20 for HNT). Nineteen loci were detected with the relative changes in the traits between control and HNT. Positive phenotypic correlations and co-located genetic loci with previously cloned grain size genes revealed common genetic regulation between control and HNT, particularly grain size. Network-based predictive models prioritized 20 causal genes at the genetic loci based on known gene/s expression under HNT in rice. Our study provides important insights for future candidate gene validation and molecular marker development to enhance HNT tolerance in rice. Integrated physiological, genomic, and gene network-informed approaches indicate that the candidate genes for stay-green trait may be relevant to minimizing HNT-induced yield and quality losses during grain filling in rice by optimizing source-sink relationships.


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