1. Key Laboratory for the Physics and Chemistry of Nanodevices and Center for Carbon‐Based ElectronicsDepartment of ElectronicsPeking University Beijing 100871 China
2. Academy for Advanced Interdisciplinary StudiesPeking University Beijing 100871 China
3. Center for NanochemistryBeijing Science and Engineering Center for NanocarbonsBeijing National Laboratory for Molecular SciencesCollege of Chemistry and Molecular EngineeringPeking University Beijing 100871 P. R. China