• 文献标题:   Electronic Strengthening of Graphene by Charge Doping
  • 文献类型:   Article
  • 作  者:   SI C, DUAN WH, LIU Z, LIU F
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW LETTERS
  • ISSN:   0031-9007 EI 1079-7114
  • 通讯作者地址:   Univ Utah
  • 被引频次:   71
  • DOI:   10.1103/PhysRevLett.109.226802
  • 出版年:   2012

▎ 摘  要

Graphene is known as the strongest 2D material in nature, yet we show that moderate charge doping of either electrons or holes can further enhance its ideal strength by up to similar to 17%, based on first-principles calculations. This unusual electronic enhancement, versus conventional structural enhancement, of the material's strength is achieved by an intriguing physical mechanism of charge doping counteracting the strain induced enhancement of the Kohn anomaly, which leads to an overall stiffening of the zone boundary K-1 phonon mode whose softening under strain is responsible for graphene failure. Electrons and holes work in the same way due to the high electron-hole symmetry around the Dirac point of graphene, while overdoping may weaken the graphene by softening other phonon modes. Our findings uncover another fascinating property of graphene with broad implications in graphene-based electromechanical devices.