INFRARED
Co-Editors-in-Chief
Guilin Chen
Shi-yu FANG, Ya-rong WANG, Zhi-xin TIAN, Ji-chao SHI, Yong-zheng FANG, Chang-hong SUN, Zhen-hua YE, and Yu-feng LIU

The pseudo-binary semiconductor material of mercury cadmium telluride (HgxCd1-xTe) has excellent electro-optical characteristics,which is one of the most important materials for the preparation of high-sensitivity infrared detectors. In order to enhance the performance of HgxCd1-xTe photodetectors, various HgxCd1-xTe material preparation technologies and device manufacturing processes have been developed. However, in the preparation of various materials and device applications, the surface of HgxCd1-xTe will be affected by the environment and adverse surface effects. It is necessary to use advanced passivation technology to process its surface charge state to improve the electrical and physical properties of the material surface, thereby realize the improvement of device detection performance. Therefore, the surface passivation process of the HgxCd1-xTe thin film is very important to the performance improvement of the HgxCd1-xTe infrared detector. The growth methods of the passivation layer on the surface of HgCdTe thin films in recent years are summarized and analyzed. According to the classification and summary of the original passivation and non-intrinsic passivation, the advantages and disadvantages of different passivation methods are analyzed, and the future HgCdTe thin film passivation process is prospected.

Jan. 01, 1900
  • Vol. 42 Issue 9 1 (2021)
  • Jan. 01, 1900
  • Vol. 42 Issue 9 1 (2021)
  • Shang-shu LI, Chang-he ZHOU, and Chao XU

    Cadmium zinc telluride (CZT) is an important substrate material for mercury cadmium telluride (MCT) infrared focal plane array devices. There is a strong exothermic phenomenon during the synthesis of CZT polycrystal. Therefore, controlling the heat release is the basic condition for the smooth progress of the CZT polycrystal material synthesis process. The exothermic intensity and rate of the synthesis reaction can be effectively controlled by changing the initial tilt angle, and a large tilt angle is beneficial to obtain a slow and stable process. Based on the experimental results and thermodynamic analysis, it is shown that the synthesis reaction can be divided into two stages, including liquid-solid phase reaction and liquid-liquid phase reaction between Cd and Te. Meanwhile, the experimental results show that the amount of heat released from the synthesis reaction determines whether the second reaction will occur at high temperatures. Finally, the related mechanism of the secondary reaction is analyzed.

    Jan. 01, 1900
  • Vol. 42 Issue 9 14 (2021)
  • Zhi-hao FANG, Lei ZHANG, Zhi-kai FU, and Sen LIU

    Based on the application requirements of infrared detection systems for small-volume cooled infrared detectors, a new type of non-vacuum cooled infrared detector miniaturization packaging technology is proposed. The key points of its structure and process design are explained, the component packaging is realized, and the performance test of the coupled J-T refrigerator is carried out. The results show that the design scheme described in this article can achieve 128×128 (15μm) InSb chip packaging, the components are less than or equal to Φ20 mm×15 mm, the weight is about 5 g, and the performance is significantly improved compared with existing products. Its detection and imaging performance can meet the requirements of use. The start-up time of this component can be less than 4 s, and the cold storage time is currently 6 s. The refrigeration performance can be further optimized and improved in the follow-up study of the joint refrigerator design.

    Jan. 01, 1900
  • Vol. 42 Issue 9 21 (2021)
  • Gui-zhi LI, Hai-sa JIA, Lu HAN, and Ju-bo ZHAO

    Infrared radiometric calibration is one of the basic technologies to obtain the infrared radiation characteristics of the target. The accuracy of radiation calibration has an important influence on the subsequent target's radiation characteristic measurement. Aiming at the selection of the pixel size of the detection target during the mid-wave infrared radiation calibration, the influence on the linearity of the system during the radiation calibration is studied. Based on 640×520 mid-wave focal plane array, the central pixel, 100×100 central area, 200×200 central area and the whole target area are selected for research. In the high temperature section, the random error in the 20×20 area is 5.27%, and the minimum error in the center pixel 100×100 area is 0.01%. In the low temperature section, the random error of the 20×20 area is 1.78%, and the minimum error in the center pixel 100×100 area is 0.45%. In a certain target area, as the selected target surface increases, the error gradually decreases. The research results have certain engineering application value for the selection of infrared detector radiation calibration target surface.

    Jan. 01, 1900
  • Vol. 42 Issue 9 26 (2021)
  • Ya-jun LI, Wei ZHENG, Jie CHEN, Shi-hao TANG, and Cheng LIU

    At present, fire detection based on satellite remote sensing mainly use the mid-infrared band data with the resolution of kilometer level, but the quantitative research on the detection sensitivity of different infrared bands is very few. This is not conducive to give full play to the role of infrared band information in fire monitoring. In this paper, the mixed pixel decomposition method is used for the first time to quantitatively analyze the differences of different infrared bands with resolution of 150 m, 300 m and 1 km in the application of fire spot monitoring. The results show that the sensitivity of the mid-infrared channel with a resolution of 150 m is about 30 times higher than that of the channel with a resolution of 1 km.The far-infrared channel with the resolution of 300 m can detect the fire point of 100 square meters level and the short-wave infrared channel with a resolution of 150 m has obvious response to high intensity open fire area. In this paper, the infrared data of meteorological satellite with a resolution of 1 km and environmental disaster mitigation satellite with a resolution of 150 m as well as 300 m are used to monitor the forest fire in Xunke County of Heilongjiang province in spring and straw burning in Anhui province in summer of 2009, so as to verify the conclusions above. The results show that improving the resolution of infrared band obviously improves the application ability of satellite remote sensing in very small fire spot detection, fire dynamic monitoring, and fire condition assessment.

    Jan. 01, 1900
  • Vol. 42 Issue 9 30 (2021)
  • Xia ZHANG, Guo-fei SHANG, Yan-li GAO, Hui-min WANG, and Yong-rong ZHANG

    Aiming at ground targets thermal infrared and polarization radiation characteristics of remote sensing detection requirements, soil is taken as the research object which is one of the five typical ground targets in this paper. The ground object thermal infrared multi-angle polarization remote sensing measurement platform and instrument are used to obtain the thermal infrared multi-angle thermal radiation and polarization radiation data of soil under the influence of different factors. In addition, the characteristics of soil thermal and polarization radiation are studied from five aspects of detection angle, azimuth angle, wave band, polarization angle and soil type. The results show that when the incident light source is fixed, the radiance and brightness temperature of the soil increase with the increase of detection angle. When the azimuth angle is 180°, both of them reach the maximum value. And they show different laws with the change of wave band. The influence of polarization angle and soil type on radiance is not significant, but the influence on brightness temperature is significant. The research results can provide new ideas and methods for the application of thermal infrared soil remote sensing, and provide important theoretical support for the further development of thermal infrared and polarization remote sensing.

    Jan. 01, 1900
  • Vol. 42 Issue 9 42 (2021)
  • Please enter the answer below before you can view the full text.
    8+1=
    Submit