scholarly journals Responsivity Enhanced NMOSFET Photodetector Fabricated by Standard CMOS Technology

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Fuwei Wu ◽  
Xiaoli Ji ◽  
Feng Yan
Keyword(s):  
Dark Current ◽  
Light Condition ◽  
Cmos Technology ◽  
Gain Factor ◽  
Experimental Results ◽  
Low Light ◽  
Large Gain ◽  
Promising Application ◽  
Weak Light

Increasing the responsivity is one of the important issues for a photodetector. In this paper, we demonstrate an improved NMOSFET photodetector by using deep-n-well (DNW) structure which can improve the responsivity of the photodetector significantly. The experimental results show that the responsivity can be enhanced greatly by the DNW structure and is much larger than the previous work when DNW is biased with 0.5 V, while the dark current exhibits almost no increase. Further characterization indicates that the diode formed by the bulk and DNW can efficiently absorb photons and has a large gain factor of the photocurrent especially under low light condition, which gives a more promising application for the detector to detect the weak light.

scholarly journals Response of Photosynthesis and Chlorophyll Fluorescence Parameters of Castanopsis kawakamii Seedlings to Forest Gaps

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Zhong-sheng He ◽  
Rong Tang ◽  
Meng-jia Li ◽  
Meng-ran Jin ◽  
Cong Xin ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Light Intensity ◽  
Seedling Growth ◽  
Group Treatment ◽  
Control Group ◽  
Low Light ◽  
Chlorophyll Fluorescence Parameters ◽  
Forest Gaps ◽  
Low Light Intensity ◽  
Weak Light

Light is a major environmental factor limiting the growth and survival of plants. The heterogeneity of the light environment after gap formation in forest influences the leaf chlorophyll contents, net photosynthetic rate (Pn), and chlorophyll fluorescence, thus influencing the growth and regeneration of Castanopsis kawakamii seedlings. The aim of this study was to explore the effects of weak light on the photosynthetic physiology of C. kawakamii seedlings in forest gaps and non-gaps. The results showed that (1) the contents of chlorophyll a (Chl-a), chlorophyll b (Chl-b), and total chlorophyll (Chl-T) in forest gaps were lower than in non-gaps. Seedlings tended to increase chlorophyll content to absorb light energy to adapt to low light intensity in non-gap environments. (2) The Pn values of C. kawakamii seedlings in forest gaps were significantly higher than in non-gaps, and forest gaps could improve the seedlings’ photosynthetic capacity. (3) The C. kawakamii seedlings in forest gaps were more sensitive to weak light and control group treatment, especially the tall seedlings, indicating that seedlings require more light to satisfy their growth needs in the winter. The seedlings in non-gaps demonstrated better adaptability to low light intensity. The light intensity was not adequate in weak light conditions and limited seedling growth. We suggest that partial forest selection cutting could improve light intensity in non-gaps, thus promoting seedling growth and regeneration of C. kawakamii more effectively in this forest.

Molecular Simulation on Interfacial Structure and Gettering Efficiency of Si (110)/(100) Directly Bonded Hybrid Crystal Orientation Substrates

2009 ◽  
Vol 156-158 ◽  
pp. 199-204
Author(s):  
Hiroaki Kariyazaki ◽  
Tatsuhiko Aoki ◽  
Kouji Izunome ◽  
Koji Sueoka
Keyword(s):  
Molecular Simulation ◽  
Wafer Bonding ◽  
Crystal Orientation ◽  
High Performance ◽  
Cmos Technology ◽  
Experimental Results ◽  
Interfacial Structure ◽  
Atomic Configuration ◽  
Promising Technology ◽  
Bonded Interface

Hybrid crystal orientation technology (HOT) substrates comprised of Si (100) and (110) surface orientation paralleling each <110> direction attract considerable attentions as one of the promising technology for high performance bulk CMOS technology. Although HOT substrates are fabricated by wafer bonding of Si (110) and Si (100) surfaces, it is not clear the atomic configuration of interfacial structure. Furthermore, the possibility for the interface to be an effective gettering source of impurity metals was not well studied. In this paper, we studied the interfacial structure and gettering efficiency of the atomic bonded interface by molecular simulations. The results indicate that the simulated atomic configuration and gettering efficiency of the bonded interface agreed well with the experimental results.

AN INTEGRATED CHUA'S CELL FOR THE IMPLEMENTATION OF A CHUA'S ARRAY

2004 ◽  
Vol 14 (01) ◽  
pp. 93-105 ◽  
Author(s):  
PAOLO ARENA ◽  
SALVATORE CASTORINA ◽  
LUIGI FORTUNA ◽  
MATTIA FRASCA ◽  
ALESSANDRO RIZZO
Keyword(s):  
Complex Systems ◽  
Single Cell ◽  
Chaotic Attractor ◽  
Cmos Technology ◽  
Experimental Results ◽  
External Control ◽  
Chaotic Oscillations ◽  
Frequency Range ◽  
Array Design ◽  
Chip Area

In this paper a new integrated Chua's circuit is implemented through switched-capacitor techniques. Recent studies on complex systems made of vast arrays or matrices of Chua's cells motivate the need for experimental verifications which could be easily accomplished by an integrated version of the array. Design efforts have been devoted to the reduction of the chip area consumption. The cell layout, realized in CMOS technology, is presented and experimental results confirm the validity of our chip implementation. The implementation presented allows the user to generate a wide gallery of complex behaviors. The system is in fact programmable: both the chaotic attractor generated by the single cell and the frequency range of the chaotic oscillations can be easily set via external control pins.

Ultrasensitive broadband photodetectors based on two-dimensional Bi2O2Te films

2021 ◽  
Author(s):  
Pin Tian ◽  
Hongbo Wu ◽  
Libin Tang ◽  
Jinzhong Xiang ◽  
Rongbin Ji ◽  
...  
Keyword(s):  
Large Scale ◽  
2D Materials ◽  
Complementary Metal Oxide Semiconductor ◽  
Cmos Technology ◽  
Photocurrent Density ◽  
Short Wave ◽  
Oxide Semiconductor ◽  
Light Illumination ◽  
Two Dimensional ◽  
Weak Light

Abstract Two-dimensional (2D) materials exhibit many unique optical and electronic properties that are highly desirable for application in optoelectronics. Here, we report the study of photodetector based on 2D Bi2O2Te grown on n-Si substrate. The 2D Bi2O2Te material was transformed from sputtered Bi2Te3 ultrathin film after rapid annealing at 400 ℃ for 10 min in air atmosphere. The photodetector was capable of detecting a broad wavelength from 210 nm to 2.4 μm with excellent responsivity of up to 3x105 and 2x104 AW-1, and detectivity of 4x1015 and 2x1014 Jones at deep ultraviolet (UV) and short-wave infrared (SWIR) under weak light illumination, respectively. The effectiveness of 2D materials in weak light detection was investigated by analysis of the photocurrent density contribution. Importantly, the facile growth process with low annealing temperature would allow direct large-scale integration of the 2D Bi2O2Te materials with complementary metal-oxide–semiconductor (CMOS) technology.

scholarly journals High responsivity in MoS2 phototransistors based on charge trapping HfO2 dielectrics

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Roda Nur ◽  
Takashi Tsuchiya ◽  
Kasidit Toprasertpong ◽  
Kazuya Terabe ◽  
Shinichi Takagi ◽  
...  
Keyword(s):  
Transition Metal Dichalcogenides ◽  
Charge Trapping ◽  
Dual Function ◽  
Light Illumination ◽  
Low Light ◽  
High Responsivity ◽  
Metal Dichalcogenides ◽  
High Resolution Images ◽  
Weak Light ◽  
Light Signals

Abstract2D Transition Metal Dichalcogenides hold a promising potential in future optoelectronic applications due to their high photoresponsivity and tunable band structure for broadband photodetection. In imaging applications, the detection of weak light signals is crucial for creating a better contrast between bright and dark pixels in order to achieve high resolution images. The photogating effect has been previously shown to offer high light sensitivities; however, the key features required to create this as a dominating photoresponse has yet to be discussed. Here, we report high responsivity and high photogain MoS2 phototransistors based on the dual function of HfO2 as a dielectric and charge trapping layer to enhance the photogating effect. As a result, these devices offered a very large responsivity of 1.1 × 106 A W−1, a photogain >109, and a detectivity of 5.6 × 1013 Jones under low light illumination. This work offers a CMOS compatible process and technique to develop highly photosensitive phototransistors for future low-powered imaging applications.

scholarly journals Fractional-Order Fusion Model for Low-Light Image Enhancement

Symmetry ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 574 ◽  
Author(s):  
Qiang Dai ◽  
Yi-Fei Pu ◽  
Ziaur Rahman ◽  
Muhammad Aamir
Keyword(s):  
Image Enhancement ◽  
Fractional Order ◽  
Input Image ◽  
Experimental Results ◽  
Fusion Model ◽  
Low Light ◽  
Visual Appearance ◽  
Light Image ◽  
Proposed Model ◽  
Detail Enhancement

In this paper, a novel fractional-order fusion model (FFM) is presented for low-light image enhancement. Existing image enhancement methods don’t adequately extract contents from low-light areas, suppress noise, and preserve naturalness. To solve these problems, the main contributions of this paper are using fractional-order mask and the fusion framework to enhance the low-light image. Firstly, the fractional mask is utilized to extract illumination from the input image. Secondly, image exposure adjusts to visible the dark regions. Finally, the fusion approach adopts the extracting of more hidden contents from dim areas. Depending on the experimental results, the fractional-order differential is much better for preserving the visual appearance as compared to traditional integer-order methods. The FFM works well for images having complex or normal low-light conditions. It also shows a trade-off among contrast improvement, detail enhancement, and preservation of the natural feel of the image. Experimental results reveal that the proposed model achieves promising results, and extracts more invisible contents in dark areas. The qualitative and quantitative comparison of several recent and advance state-of-the-art algorithms shows that the proposed model is robust and efficient.

The Gray Processing of Moon Digital Orthophoto Map

2012 ◽  
Vol 182-183 ◽  
pp. 2113-2117
Author(s):  
Wu Jian Xu ◽  
Hao Sheng ◽  
Chen Lou ◽  
Hui Jie Zhao
Keyword(s):  
Light Condition ◽  
Statistical Information ◽  
Experimental Results ◽  
Gray Level ◽  
Visual Effect ◽  
Longitudinal Changes ◽  
Gray Histogram ◽  
Digital Orthophoto ◽  
Distribution Problems

Considering the mosaic result of the lunar DOM (Digital Orthophoto Map) produced by China's “CE-1” satellite, there usually exists a sharp gray jump beside the joining line. As to a strip image, the gray distribution may be uneven because of the light changing or position difference during photographing. To solve these matters, a method was proposed which is based on dynamic rules to detect the best joining line, and then stretch image according to its gray histogram. By making the pixels around boundary to change gradually, the joining line will finally be invisible. In order to solve the uneven gray distribution problems causing by imaging angle, light condition and other factors, a homogenization technology based on statistics of gray distribution was proposed. Using statistical information of the bands’ longitudinal changes to united the gray level to a defaulted range. The experimental results show that the method of this paper can make the integral gray level become even, the transition become more gently, and visual effect become more natural.

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