1. Gansu Province Organic Semiconductor Materials and Applied Technology Research Center School of Material Science and Engineering Lanzhou Jiaotong University Lanzhou 730070 PR China
2. College of Petroleum and Chemical Engineering Jilin Institute of Chemical Technology Jilin 432000 P. R. China
3. Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong University Lanzhou 730070 PR China
4. Gansu Province Organic Semiconductor Materials and Applied Technology Research Centre Lanzhou Jiaotong University Lanzhou 730070 PR China