1. Institute of Flexible Electronics Technology of THU, Tsinghua University, Jiaxing, Zhejiang 314000, P.R. China
2. School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
3. Institute of Materials Research and Engineering, Agency for Science, Technology and Research, Singapore 138634, Singapore
4. Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research, Singapore 138634, Singapore
5. Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
6. Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing 100084, P.R. China
7. School of Microelectronics, Shanghai University, Shanghai 201800, P.R. China