1. Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM) Nanjing Tech University (NanjingTech) 30 South Puzhu Road Nanjing 211816 China
2. Department of Materials Science and Engineering National University of Singapore Singapore 117575 Singapore
3. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
4. Frontiers Science Center for Flexible Electronics (FSCFE) Shaanxi Institute of Flexible Electronics (SIFE) and Shaanxi Institute of Biomedical Materials and Engineering (SIBME) Northwestern Polytechnical University (NPU) 127 West Youyi Road Xi'an 710072 China