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Circuit architecture and pixel array arrangement. Pixels were arranged in a checker pattern to facilitate the differential signal extraction. A lateral overflow integration capacitor (LOFIC) was implemented in each pixel.
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This paper presents a complementary metal-oxide-semiconductor (CMOS) image sensor (CIS) capable of capturing UV-selective and visible light images simultaneously by a single exposure and without employing optical filters, suitable for applications that require simultaneous UV and visible light imaging, or UV imaging in variable light environment. T...
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... simulations carried out were the charge transfer from inside the photodiode to the transfer gate, simulated by analyzing the potential inside the photodiode to check for potential pockets capable of trapping the charges during transfer operation, and spectral internal quantum efficiency (internal QE) in the waveband of 200-1000 nm. Figure 2 summarizes the circuit block diagram of the developed CIS and the pixel array arrangement. The pixel structure is similar to a 4T pixel, but with an S switch and a lateral overflow integration capacitor (LOFIC) [31] added to achieve high dynamic range by performing charge-voltage conversion in the small floating diffusion (FD) capacitance in low light illumination, and in the large FD + LOFIC capacitance in strong light conditions. ...
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This study proposes a new ultraviolet-infrared (UV-Ir) compatible sensor fabricated using the standard CMOS process. The concept is verified through a numerical simulation, wherein the standard CMOS process parameters used are evaluated. The proposed sensor is an extension of a previously proposed RGB sensor designed on the standard CMOS process, a...
Citations
... Currently, the main production companies of CMOS sensor products are E2V, Dalsa, CMOSIS, etc., whose products have reached the highest resolution of billion pixels [7][8]. It is developing in the direction of higher resolution, higher sensitivity, wider dynamic range, more miniaturization and digitalization. ...
The ultra-large-scale CMOS image sensors are significantly different from the traditional CMOS image sensors in terms of pixel size, chip size and structure. CMOS image sensors generally come with an optical window structure that is sealed to the ceramic housing by means of adhesive. The optical window material is generally sapphire, and the larger the image element size, the larger the required glass optical window area. Ultra-large size CMOS image sensors in the package before the general optical window thickness, parallelism, light window average transmittance assessment. The object of mechanical impact test assessment is the CMOS image sensor optical window structure and capping process. The paper mainly discusses the typical failure cases of ultra-large-scale CMOS image sensors on the basis of the applicability of mechanical shock test standards, and investigates how to define the mechanical shock test stress from simulation, limit test and the requirements by users. This paper provides the qualification assessment basis of mechanical shock for newly developed products.
... Alternatively, implementations based on silicon-on-insulator 2 or ultrashallow junctions 3 exist, which exploit the thin film that transmits light with longer wavelengths. Furthermore, UV selectivity can be achieved by elegant readout approaches, such as the use of a differential method 4,5 . By instead using wide-bandgap materials as the substrate, the sensitive spectral bandwidth of the semiconductor is reduced to shorter wavelengths. ...
This work demonstrates the first on-chip UV optoelectronic integration in 4H-SiC CMOS, which includes an image sensor with 64 active pixels and a total of 1263 transistors on a 100 mm 2 chip. The reported image sensor offers serial digital, analog, and 2-bit ADC outputs and operates at 0.39 Hz with a maximum power consumption of 60 μW, which are significant improvements over previous reports. UV optoelectronics have applications in flame detection, satellites, astronomy, UV photography, and healthcare. The complexity of this optoelectronic system paves the way for new applications such harsh environment microcontrollers.
... There is also experience in developing single-exposure image sensors for the simultaneous acquisition of UV and visible images without using optical filters by employing lowand high-sensitivity pixel types arranged in a checkered pattern, from which the UV and visible images can be generated [126]. ...
... This strategy could avoid the use of image intensifiers or photomultipliers, which increase the cost of the entire system and often require high-voltage supply and external cooling, thus increasing the size, weight, cost, and power consumption. Another possibility is to develop single-exposure image sensors for the simultaneous acquisition of UV and visible images without optical filters using approaches inspired by [126] or other possibilities open for research. Therefore, drastic reductions in cost, power consumption, volume, and weight are required, especially to install a network of corona imagers for the automatic inspection of high-, medium-, and low-voltage assets in an IoT-compatible approach. ...
Today, there are many attempts to introduce the Internet of Things (IoT) in high-voltage systems, where partial discharges are a focus of concern since they degrade the insulation. The idea is to detect such discharges at a very early stage so that corrective actions can be taken before major damage is produced. Electronic image sensors are traditionally based on charge-coupled devices (CCDs) and, next, on complementary metal oxide semiconductor (CMOS) devices. This paper performs a review and analysis of state-of-the-art image sensors for detecting, locating, and quantifying partial discharges in insulation systems and, in particular, corona discharges since it is an area with an important potential for expansion due to the important consequences of discharges and the complexity of their detection. The paper also discusses the recent progress, as well as the research needs and the challenges to be faced, in applying image sensors in this area. Although many of the cited research works focused on high-voltage applications, partial discharges can also occur in medium- and low-voltage applications. Thus, the potential applications that could potentially benefit from the introduction of image sensors to detect electrical discharges include power substations, buried power cables, overhead power lines, and automotive applications, among others.
... However, the drawbacks of this approach include high costs and difficulty in integration. Recently, the Si-based filter-less UV detector was developed, wherein two photodiodes with different sensitivity to the UV light [6], [7] were used and realized as a discrete package. This implies that there is still considerable research required to realize the integration of UV sensors into LSI systems. ...
This study proposes a new ultraviolet-infrared (UV-Ir) compatible sensor fabricated using the standard CMOS process. The concept is verified through a numerical simulation, wherein the standard CMOS process parameters used are evaluated. The proposed sensor is an extension of a previously proposed RGB sensor designed on the standard CMOS process, and calculating the current ratio enables the detection of UV with high sensitivity. In addition, the use of current rectification eliminates the short to middle wavelength region and leaves only the Ir region which is used for detection. High dynamic ranges of 160 dB are ensured for all UV, Ir and RGB which they are excellent for color sensing. Consequently, combined with the previously proposed RGB sensing, the new RGB+UV+Ir sensor is realized without any filters.
A novel photodetector for imaging in the visible–near infrared range is investigated. Unlike currently used detectors, the proposed device does not require thin-film filters for spectral discrimination. Instead, the discrimination relies on the wavelength-dependent absorption property of semiconductor materials. The detector consists of a window exposing the silicon substrate to the electromagnetic signal. Besides the window, multiple collectors separated by polysilicon gates are laid out. Proper voltage biasing establishes a different spectral response for each collector, thus creating a detection color space. Experimental results demonstrate the color detection capability of a three-collector imaging pixel from sensitivity metamerism index calculations. The sensor is fabricated in a standard 0.35-
$\mu \text{m}$
CMOS process and presents a peak combined collectors’ responsivity of 0.35 A/W.
