Original achievement is an important symbol to measure the academic level of research universities. In 2003, the research group led by Academician Qin Guogang made an important original theoretical achievement on the luminescence of nano-silicon/silica material system, which was recently proved by experiments.

Since 1990 discovered that porous silicon emits strong visible light at room temperature, people have dreamed of using nano-silicon/silicon oxide system as the light source of silicon optoelectronics. However, the luminescence process of the system is quite complicated, and electron-hole pairs can be combined in nano-silicon, or transferred to the interface luminescence center of nano-silicon/silicon oxide. From 65438 to 0999, the famous research group led by Fauchet of the University of Rochester in the United States cooperated with Allan and Delerue, famous French solid theorists, and published an article in Physical Review Letters, pointing out that when nano-silicon is large, the internal luminescence of nano-silicon is dominant; However, when nano-silicon is small, the luminescence center at the nano-silicon/silicon oxide interface is dominant. This paper has a wide influence in the world, and its views are widely accepted. It has been cited by SCI for 38 1 time.

1993, Academician Qin Guogang and Dr. Jia Yongqiang proposed the quantum confinement/luminescence center model. In 2003, Academician Qin Guogang and Dr. Li Yujie continued their research on the basis of this theory, and reached a conclusion contrary to Fauchet et al. (Physical Review, vol. 68, 085309, 2003): When nano-silicon is large, the luminescence center at the interface between nano-silicon and silica is dominant; When nano-silicon is small, the internal luminescence of nano-silicon is dominant. In June, 2005, 5438+065438+ 10, Academician of Institute of Semiconductors of Chinese Academy of Sciences cooperated with Professor Ge of Hong Kong University of Science and Technology, and made a systematic study on nano-silicon/silica system by using temperature-changing fluorescence and high-resolution electron microscope (Physical Review, vol. 72, 1953 13, etc. And study its variation law with the size of nano-silicon, and clearly point out that the experimental results support the theoretical prediction of the above-mentioned academician Qin Guogang (the abstract of the paper points out: "The larger the size of Sincs[ nanocrystals] is, the higher the density of interface states (in particle, Si=Obonds), then the molecular potential or interface state recombination process exceeds the quantumconfinementprocess, which is different from Qin's prediction of Qinan Li[phys. rev? B68,85309 (2003)].