1. Shaanxi Institute of Flexible Electronics (SIFE)Northwestern Polytechnical University (NPU) 127 West Youyi Road Xi'an Shaanxi 710072 China
2. Joint Key Laboratory of the Ministry of EducationInstitute of Applied Physics and Materials EngineeringUniversity of MacauAvenida da Universidade Taipa Macao S. A. R. 999078 China