• 文献标题:   Impact of Auger processes on carrier dynamics in graphene
  • 文献类型:   Article
  • 作  者:   WINZER T, MALIC E
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   1098-0121 EI 1550-235X
  • 通讯作者地址:   Tech Univ Berlin
  • 被引频次:   97
  • DOI:   10.1103/PhysRevB.85.241404
  • 出版年:   2012

▎ 摘  要

Auger processes are of great importance for both fundamental research and technological applications, since they change the number of charge carriers in a system. Here, we present a microscopic study on the influence of Auger relaxation channels on the carrier dynamics in graphene. The presented time-, momentum-, and angle-resolved calculations reveal the importance of the impact excitation giving rise to a significant multiplication of optically excited carriers and a remarkable Coulomb-induced carrier cooling effect. We propose low pump fluence, high excitation energy, and low ambient temperature as optimal conditions for an efficient carrier multiplication reaching values of up to 2.5 even in the presence of phonons. The optimal regime is confirmed by an analytic expression for the carrier multiplication, which gives further insights into the role of Auger processes for a Dirac-like carrier system. Our results can help to guide future experiments to demonstrate the carrier multiplication in graphene and related structures.