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2023
Volume: 44 Issue 3
8 Article(s)
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Study on Mesa Etching Technology for Type-II Superlattice Materials with Low Damage and High Aspect Ratio
Jing-feng LI, Ming LIU, Hai-yan LI, Tao WEN, Cheng-cheng ZHAO, and Dan WANG
The fabrication of type-II superlattice infrared detectors with a dual color single indium column structure is difficult and prone to damage during the mesa forming process, which affects the performance of the device. In order to solve this problem, the mesa etching technology for type-II superlattice materials with lThe fabrication of type-II superlattice infrared detectors with a dual color single indium column structure is difficult and prone to damage during the mesa forming process, which affects the performance of the device. In order to solve this problem, the mesa etching technology for type-II superlattice materials with low damage and high aspect ratio was studied. Firstly, a damage judgment mechanism is established to determine whether the material has inversion after etching in the existing process. By optimizing the photoresist thickness and variable power step etching, the mesa etching of type-II superlattice materials with low damage and high aspect ratio is realized, while effectively solving the process problems such as easy accumulation of products and excessively steep sidewalls in single etching of deep mesas. The distance between centers of mesa is 20 m. Etching depth exceeds 8 m. The gap depth to width ratio can reach 2. The devices subsequently fabricated on this mesa have significant dual impedance characteristics, with a peak long wave impedance of 100 MΩ, and a flat region on the long wave side of the I-V curve exceeding 100 mV. From the perspective of electricity, it is preliminarily judged that the detector has the ability of dual color detection, and the feasibility of this process is verified..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 3, 1 (2023)
Research on CdSexTe1-x Molecular Beam Epitaxy Technology
Wen HE, Cong WANG, Da GAO, Wei-rong XING, Wei BAI, Hai-yan YANG, and Wei-lin SHE
The molecular beam epitaxial growth conditions and component adjustment of CdSexTe1-x substrate material for HgCdTe infrared detectors are briefly introduced. Growth conditions include growth structure (mainly CdSexTe1-x/CdTe/ZnTe/Si, CdSexTe1-x/ZnTe/GaAs, etc.), growth temperature (about 300℃), and growth thickness (aThe molecular beam epitaxial growth conditions and component adjustment of CdSexTe1-x substrate material for HgCdTe infrared detectors are briefly introduced. Growth conditions include growth structure (mainly CdSexTe1-x/CdTe/ZnTe/Si, CdSexTe1-x/ZnTe/GaAs, etc.), growth temperature (about 300℃), and growth thickness (about 5 m ), etc. Component adjustment includes analyzing the changes of Se components with (JSe+JTe)/JCd and JSe/(JSe+JTe). When the JSe/(JSe+JTe) value is small, it is difficult for the Se component to incorporate into the epitaxial layer. When the JSe/(JSe+JTe) value is large, the Se component increases rapidly. At the same time, when the JSe/(JSe+JTe) value is small, the growth trend of the Se component is relatively easy to control. When the value of JSe/(JSe+JTe) is constant, the Se component increases with the decrease of (JSe+JTe)/JCd. The sudden increase point of Se component change increases with the decrease of (JSe+JTe)/JCd value. This paper can provide some reference for the preparation of high-performance HgCdTe infrared detectors..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 3, 8 (2023)
Study on In-Doped HgCdTe on Silicon Substrate by Molecular Beam Epitaxy
Dan WANG, Zhen LI, Da GAO, Wei-rong XING, Xin WANG, and Wei-lin SHE
In-doped mercury cadmium telluride (MCT) material was grown using a molecular beam epitaxy (MBE) system. High quality MCT epitaxial wafers with different doping levels were obtained by controlling the In source temperature. The secondary ion mass spectrometer (SIMS) test results show that the concentration of In dopingIn-doped mercury cadmium telluride (MCT) material was grown using a molecular beam epitaxy (MBE) system. High quality MCT epitaxial wafers with different doping levels were obtained by controlling the In source temperature. The secondary ion mass spectrometer (SIMS) test results show that the concentration of In doping is between 1×1015 cm-3 and 2×1016 cm-3. The effect of different In doping concentrations on dislocations in the MCT epitaxial layer was characterized. It is found that the dislocation etch pits are mainly triangular in shape, arranged in the direction of <111>. The dislocation density is approximately the same as that of the undoped sample. The electrical properties of the samples were improved after mercury saturation low-temperature treatment for materials with different In doping concentrations. The results confirm that In doping can improve the homogeneity of the material, thereby obtaining a higher electron mobility..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 3, 14 (2023)
Research on Ghosting of Highlight Point Target of Cooled Infrared Imager
Peng ZHANG, Chuan-lin TANG, Lin-huai XIANG, Zhi-bin HU, Peng LIU, Xing-rong ZENG, and Xue-su WANG
With the development of high resolution cooled infrared thermal imager, the frequency of analog signal has been improved. This leads to the need to ensure the quality of analog signals along the transmission path, so as to ensure the imaging quality of infrared images. In the imaging experiment of 1280×1024@15 m mWith the development of high resolution cooled infrared thermal imager, the frequency of analog signal has been improved. This leads to the need to ensure the quality of analog signals along the transmission path, so as to ensure the imaging quality of infrared images. In the imaging experiment of 1280×1024@15 m medium-wave thermal imager, it is found that the highlighted point source objects in infrared images appear in pairs. It means that the ghosting appears. This causes serious interference to the detection and identification of smaller targets. In this paper, the simulation signal transmission path model and the simulation circuit signal are extracted and the infrared images are further compared. It is found that the impedance mismatch on the signal transmission path is the main cause of image ghosting, and it is verified that when the matching resistance on the transmission path is between 40 Ω and 70 Ω, the signal transmission quality is better, and the infrared image ghosting problem can be solved..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 3, 20 (2023)
Research on Mathematical Modeling and Key Algorithms of DG Laser Seeker
Wei LI, and Kai YANG
"Red Earth" domestic seeker is taken as an example, and the structure, work flow and tracking principle of the dynamic gyro laser seeker are introduced in detail. The mathematical model and modeling process of the laser seeker are described, and its application in rocket, ground missile, aviation bomb and oth"Red Earth" domestic seeker is taken as an example, and the structure, work flow and tracking principle of the dynamic gyro laser seeker are introduced in detail. The mathematical model and modeling process of the laser seeker are described, and its application in rocket, ground missile, aviation bomb and other platforms is studied according to the characteristics of its dynamic gyro-stabilized platform. For the non-rotating missile controlled by tilting stable three-channel, the dispersion of seeker output slope can be effectively reduced by the seeker output slope compensation algorithm. For the rotating missile with dual-channel control, the seeker speed adaptive algorithm is proposed to realize the adaptive operation of the dynamic gyrostabilized platform laser seeker when the body speed is in the range of 0--10 r/s. The two algorithms have passed the simulation test and completed the engineering application after ground joint test and flight test..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 3, 29 (2023)
Research on Spatiotemporal Distribution of Eutrophication in Dianshan Lake Based on Multi-Source Satellite Data
Jun LIU, Hao-qiang QI, Ben HUANG, and Lei DONG
Accurate monitoring of cyanobacterial blooms is the basis of lake eutrophication research, which can provide a basis for the management and decision-making of water environment departments. In this paper, Dianshan Lake is chosen as the research object, Sentinel-2/MSI and Landsat-8/OLI image data are used to monitor a tAccurate monitoring of cyanobacterial blooms is the basis of lake eutrophication research, which can provide a basis for the management and decision-making of water environment departments. In this paper, Dianshan Lake is chosen as the research object, Sentinel-2/MSI and Landsat-8/OLI image data are used to monitor a total of 21 algal bloom areas in Dianshan Lake from 2019 to 2021 through the improved floating algae index (FAI). The distribution of eutrophication in Dianshan Lake is also analyzed. The results show that cyanobacteria blooms and eutrophication have appeared in Dianshan Lake for three consecutive years. The high incidence period of cyanobacteria blooms in this lake is from June to September each year. The area of eutrophication is large and the frequency is high. In September 2020 and August 2021, the bloom area exceeds 20km2.The blooms burst quickly and last for a short time..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 3, 36 (2023)
Research Progress of Drug Detection Based on Infrared Spectroscopy
Jie JIN
The research and application of infrared spectroscopy in the field of drug detection are focused on in this paper. ATR-FTIR used for qualitative analysis of drugs and classification of mixed drugs, and near-infrared spectroscopy used for quantitative and traceability analysis of drugs are introduced. By virtue of its cThe research and application of infrared spectroscopy in the field of drug detection are focused on in this paper. ATR-FTIR used for qualitative analysis of drugs and classification of mixed drugs, and near-infrared spectroscopy used for quantitative and traceability analysis of drugs are introduced. By virtue of its characteristics of accuracy, simplicity, rapidity and practicality, infrared spectrum is effectively combined with a variety of stoichiometric algorithms, which can further provide quantitative indicators for the judgment, classification and tracing of drugs. With the further integration with artificial intelligence technologies such as machine learning and neural networks, infrared spectroscopy technology will play a huge role in the future laboratory analysis and rapid field detection of drugs..
INFRARED
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 3, 42 (2023)
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