【Member News】Zhang Rong, Professor of Xiamen University: Wide band gap semiconductor ultraviolet photodetector

      Recently, with the theme of "Building ultraviolet emerging formats and promoting the transformation of scientific and technological achievements", the "Third Ultraviolet LED International Conference and Changzhi LED Industry Development Promotion Conference" was held in Changzhi, Shanxi. The meeting was hosted by Changzhi Municipal People's Government, Zhongguancun Semiconductor Lighting Engineering Research and Development and Industry Alliance (CSA), Changzhi Municipal Development and Reform Commission, Changzhi National High-tech Industrial Development Zone Management Committee.

      At the opening meeting, Zhang Rong, secretary of the Party Committee and professor of Xiamen University, brought the theme report of "wide band gap semiconductor photodetector", and shared the latest progress of AlGaN based, SiC based high-performance ultraviolet detector, Ga₂O₃ based ultraviolet detector, highly sensitive space ultraviolet detection imaging and other technologies in detail. Wide band gap semiconductor is the preferred material of UV detector, with high quantum efficiency, wide band gap, solid state device, can be used in harsh environment and other characteristics. SiC is suitable for visible light blind detection (wavelength < 400nm), AIxGa1-xN (x≥0.4) can achieve intrinsic Solar-blind detection (wavelength ≤280nm). At present, the wide bandgap semiconductor photodetectors are faced with the key scientific and technical challenges such as the influence of defects and polarization on carrier transport and collision ionization in strong fields, the internal electric field regulation and dark current suppression technology, and the consistency of Multi-part component characteristics.

      The paper introduces the research progress of AlGaN based high performance UV detector technology and points out that the key performance indicators of AlGaN Solar-blind UV avalanche photodetector, gain and dark current are the international leading level at present.

      In the research of SiC single photon detector, the homogeneous epitaxial growth of Silicon Carbide based on domestic substrate has been successfully achieved by overcoming the problems of higher stress, easier cracking and more difficult to control thickness uniformity of epitaxial layer on 8-inch substrate. A new structure of hole-induced avalanche and semi-mesa terminal is proposed. A Silicon Carbide UV single photon detector with operating temperature up to 150℃ has been successfully developed for the first time. A new method of avalanche gain fluctuation compensation is proposed, and the largest zero-blind element 1×128 UV photon counting linear array detector has been developed for the first time. It has been successfully applied in solar blind photon counting UV imager.

      In the research of extreme ultraviolet detector, the gradient doping induced shallow junction technology is proposed, and the high-reliability SiC EUV detector is successfully developed, which realizes the efficient detection of 13.5nm extreme ultraviolet light. It has taken the lead in achieving productization, breaking the monopoly and technical blockade of foreign extreme ultraviolet detectors, and has been applied in synchrotron radiation devices in Beijing and many key units. Ultraviolet detection has a unique signal in the field of high-voltage line arc and corona detection, and has great performance advantages. Its large-scale promotion is based on high-performance ultraviolet detection chips.

      In the study of Ga₂O₃-based ultraviolet detectors, he was the first to propose and establish a physical model of photoinduced interface barrier reduction, clarified the internal mechanism of the generally high external quantum efficiency of Gallium Oxide solar blind detectors, and obtained the theoretical and experimental certification of international authorities such as S.J. Pearton.

      Solar blind UV detection imaging technology has a wide range of significance in scientific research, life science, application fields and security and defense, which helps to expand the cognition of natural and man-made environments, and provides many practical application possibilities. The report further introduces the research achievements of the highly sensitive aerospace Solar-blind UV detection imaging technology.

Guest Introduction: Zhang Rong, born in Dafeng, Jiangsu Province in February 1964, is a doctor, professor and supervisor of doctoral students. He is currently the Secretary of the Party Committee of Xiamen University. He is a deputy to the 13th and 14th National People's Congress. He received his Doctor of Science degree from Nanjing University in 1995, and carried out collaborative research on wide band gap semiconductor materials at the University of Maryland and the University of Wisconsin from 1995 to 1999. Long-term commitment to semiconductor new materials, devices and physics research, has presided over the national "973" program, "863" program, National Natural Science Foundation major projects and other major research topics, was selected as the Ministry of Education "Changjiang Scholars Award Program" special professor, won the National Outstanding Young Fund, National Natural Science Foundation innovation group, the Ministry of Science and Technology key field innovation team. He is the director of the National Integrated Circuit Production-Education Integration Innovation Platform of Xiamen University, the director of the National and local Joint Engineering Research Center of Semiconductor energy-saving devices and Materials, and a member of the Academic Degree Committee of The State Council and the deputy director of the Informatics Department of the Science and Technology Committee of the Ministry of Education. He has officially published more than 400 SCI academic papers in domestic and international, been cited by SCI nearly 10,000 times, authorized more than 100 national patents, won the second prize of National Technology invention, the second prize of National Natural Science, the third prize of National Technology invention, 3 provincial and ministerial Science and Technology Progress prizes and He Liang Heli Science and Technology Progress Award. He has won the second prize of National higher education teaching achievements and two national excellent doctoral thesis nomination awards.