• 文献标题:   Ultrafast electron dynamics in twisted graphene by femtosecond photoemission electron microscopy
  • 文献类型:   Article
  • 作  者:   FUKUMOTO K, BOUTCHICH M, AREZKI H, SAKURAI K, DI FELICE D, DAPPE YJ, ONDA K, KOSHIHARA S
  • 作者关键词:   graphene multilayer, carrier dynamic, time resolved photoemission electron microscopy, lifetime
  • 出版物名称:   CARBON
  • ISSN:   0008-6223 EI 1873-3891
  • 通讯作者地址:   KEK
  • 被引频次:   3
  • DOI:   10.1016/j.carbon.2017.08.032
  • 出版年:   2017

▎ 摘  要

Twisted multilayer graphene (tMLG) present electronic properties that depend on the relative misalignment and interaction between layers. These interactions affect the band structures and the carrier dynamics upon photonic excitation. These structures are being under scrutiny and recent work high-lighted the strong potential they offer for optoelectronic devices. However, the ultrafast carrier dynamics is still at an early stage, often due to the instrumental limitations. Here, we investigated the carrier dynamics by femtosecond photoemission electron microscopy of chemical vapor deposited (CVD) twisted graphene super lattices presenting different interlayer rotation angles. The photo-generated carrier lifetimes in these selected regions show a longer lifetime compared to monolayer graphene (1 ML). This observation is assigned to the presence of band gap and sub bands in the trilayer graphene and has been supported by DFT calculations. (C) 2017 Elsevier Ltd. All rights reserved.