1. College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu 610065 P. R. China
2. Institute for Advanced Materials Deformation and Damage from Multi‐Scale Institute for Advanced Study Chengdu University Chengdu 610106 P. R. China
3. Department of Physics Department of Chemistry Department of Materials Science and Engineering and Center for 2‐Dimensional and Layered Materials The Pennsylvania State University University Park PA 16802 USA