1. Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of China Chengdu 610054 P. R. China
2. Centre Énergie Matériaux et TélécommunicationsInstitut National de la Recherche Scientifique 1650 Boulevard Lionel‐Boulet Varennes Québec J3 × 1S2 Canada
3. State Key Laboratory of Bio‐Fibers and Eco‐Textiles and College of PhysicsQingdao University No. 308 Ningxia Road Qingdao 266071 P. R. China