During my Doctoral study periods, I was hosted by Professor John Steeds (University of Bristol, UK) and Professor Li Zhihong (Tianjin University, China), and aim to understand, exploit, and develop the extremely sensitive method of low-temperature (~7K) photoluminescence microscopy for non-destructive evaluation and identification of the defects in diamond. The defects may be grown-in or created by energy-selected irradiation of specimens in a specially adapted 300 kV Transmission Electron Microscopy. The materials are of considerable interest for future applications in high-power, high-temperature, and high-frequency electronics and also for quantum information processing. I have been a lecturer of School of Materials Science and Engineering, Taiyuan University of Science and Technology since June 2012. I am now a member of the Materials Science Group, with a research portfolio based on the photoluminescence studies and first-principles simulation of the point defects in diamond, and also would like to extend our works to parallels in the optical emission from silicon carbide and cubic boron nitride. Presently I am visiting Professor Ruqian Wu at University of California, Irvine, and try to study the defects in diamond by first-principles calculation.