MOS area sensor: Part II&amp;#8212;Low-noise MOS area sensor with antiblooming photodiodes

Ohba, S.; Nakai, Masato; Ando, H.; Hanamura, S.; Shimada, Shigeru; Satoh, K.; Takahashi, K.; Kubo, M.; Fujita, Takeshi

doi:10.1109/t-ed.1980.20088

Cited by 26 publications

(5 citation statements)

References 9 publications

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“…In the case of the DM-TFTs, low-concentration NO 2 gas is insufficient for detecting distinguishable changes of electrical properties because the small fraction of total electron carriers can contribute to the reaction with NO 2 gas due to an excess electron carrier density in the active channel. This behavior is analogous to a p–n diode with a high leakage current that does not show good optical sensing performance under weak illumination due to a high background current. , However, a sufficient injection of NO 2 gas provides a meaningful drop of drain current and subsequently allows the discrimination of gas concentration from the variation rate of the drain current. However, EM-TFTs with a relatively low carrier density are expected to show a considerable change in mobile electron density even at low NO 2 gas concentrations and thus it is expected that current variation can be better detected.…”

Section: Resultsmentioning

confidence: 99%

Toward Adequate Operation of Amorphous Oxide Thin-Film Transistors for Low-Concentration Gas Detection

Kim

Ahn

Jung

et al. 2018

ACS Appl. Mater. Interfaces

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We suggest the use of a thin-film transistor (TFT) composed of amorphous InGaZnO (a-IGZO) as a channel and a sensing layer for low-concentration NO gas detection. Although amorphous oxide layers have a restricted surface area when reacting with NO gas, such TFT sensors have incomparable advantages in the aspects of electrical stability, large-scale uniformity, and the possibility of miniaturization. The a-IGZO thin films do not possess typical reactive sites and grain boundaries, so that the variation in drain current of the TFTs strictly originates from oxidation reaction between channel surface and NO gas. Especially, the sensing data obtained from the variation rate of drain current makes it possible to monitor efficiently and quickly the variation of the NO concentration. Interestingly, we found that enhancement-mode TFT (EM-TFT) allows discrimination of the drain current variation rate at NO concentrations ≤10 ppm, whereas a depletion-mode TFT is adequate for discriminating NO concentrations ≥10 ppm. This discrepancy is attributed to the ratio of charge carriers contributing to gas capture with respect to total carriers. This capacity for the excellent detection of low-concentration NO gas can be realized through (i) three-terminal TFT gas sensors using amorphous oxide, (ii) measurement of the drain current variation rate for high selectivity, and (iii) an EM mode driven by tuning the electrical conductivity of channel layers.

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Section: Resultsmentioning

confidence: 99%

Toward Adequate Operation of Amorphous Oxide Thin-Film Transistors for Low-Concentration Gas Detection

Kim

Ahn

Jung

et al. 2018

ACS Appl. Mater. Interfaces

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“…The PPS can be attributed to Noble [15] and was the first CMOS image sensor available in the market [16], [17], but its development was discontinued due to factors related with its signal-to-noise ratio (SNR). Each pixel of a PPS consists basically of a photodiode and a switching transistor.…”

Section: A Passive Pixel Sensor (Pps)mentioning

confidence: 99%

“…In the first developed PPSs, the accumulated charge was read as an output current in the horizontal line, which was later converted into a voltage by means of a resistor or a transimpedance amplifier [16], [17]. This method has some disadvantages such as: -large smear noise; -large pixel reset ( ) noise; -large fixed pattern noise.…”

Section: A Passive Pixel Sensor (Pps)mentioning

confidence: 99%

Pixel Readout Circuit for X-Ray Imagers

2010

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This paper describes the per-pixel readout circuit of an X-ray imaging matrix and compares it to other solutions. The per-pixel readout circuit consists of a digital pixel sensor array constituted by a photodiode and a one-bit first-order sigma-delta A/D converter for each pixel. The output of each pixel is a digital bit stream, containing information about the intensity of the light that falls into its photodiode. The sigma-delta A/D converters use only 19 small size MOSFETs and one capacitor. In order to perform the X-ray detection, a scintillator crystal must be placed above each photodiode for converting the X-ray energy into visible light with wavelengths near to the quantum efficiency peak of the photodiodes. Then, the visible light is converted into electronic charges by each photodiode, which is part of digital pixel sensor. The comparison between the solution presented here and other solutions show that the implemented circuit is simpler and its resolution is similar or even superior.

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“…HYBRID OPTOELECTRONIC ANALOG -TO-DIGITAL CONVERSION SYSTEM background charge generation noise in the CCD image sensor is higher than that in other large -area imaging devices, because the (29) surface of the CCD is not at thermal equilibrium.…”

Section: Design Of A/d Conversion Screenmentioning

confidence: 99%

Hybrid Optoelectronic Analog-To-Digital Conversion System

Kim

Liu

1983

Opt. Eng

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A new hybrid, direct, real -time, and parallel analog -to-digital (A /D) conversion system has been theoretically and experimentally investigated. Basically this system consists of an A/D conversion screen, a photosensor panel, a comparator, and a coder. For the purpose of designing an A/D conversion screen, various quantizer characteristics and the minimization of the mean -square distortion are briefly described. Based on the quantizer characteristics, the design algorithms of the A/D conversion screen are developed. It is found that charge -coupled device (CCD), charge-injection device (CID), and metal oxide semiconductor (MOS) photodiode image sensor arrays can be used for the large -area hybrid A/D conversion system, and photodiode or photocell arrays can be applied for a single -pixel A/D conversion system. An error analysis shows that the conversion errors result from the discrepancy between the fabricated and designed transmittance function of the screen cells and the nonuniform characteristics of the photosensors. Also, this system is theoretically compared with existing electronic A/D conversion systems. To show the feasibility of this system, a single -pixel 16 -level A/D conversion system using a single -cell 16 -level A/D conversion screen, a photosensor panel of 16 photocells, and accessory electronic circuits is designed, constructed, and experimented with input optical signals. The experimental results proved that this system can be used for achieving A/D conversion of both coherent or incoherent and monochromatic or polychromatic optical signals. The system can be potentially applied for the interface at the optical input of a digital computer for real -time optical data processing, picture coding, and optical telemetry.

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MOS area sensor: Part II—Low-noise MOS area sensor with antiblooming photodiodes

Cited by 26 publications

References 9 publications

Toward Adequate Operation of Amorphous Oxide Thin-Film Transistors for Low-Concentration Gas Detection

Toward Adequate Operation of Amorphous Oxide Thin-Film Transistors for Low-Concentration Gas Detection

Pixel Readout Circuit for X-Ray Imagers

Hybrid Optoelectronic Analog-To-Digital Conversion System

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