1. State Key Laboratory of Optoelectronic Materials and TechnologiesSchool of Electronics and Information TechnologySun Yat-sen University Guangzhou 510006 China
2. Guangdong Institute of Semiconductor Industrial TechnologyGuangdong Academy of Sciences Guangzhou 510650 China
3. School of MicroelectronicsXi'an Jiaotong University Xi'an 710049 China
4. Radiation Detection Research CenterNorthwest Institute of Nuclear Technology Xi'an 710024 China