• 文献标题:   Twisted bilayer graphene photoluminescence emission peaks at van Hove singularities
  • 文献类型:   Article
  • 作  者:   ALENCAR TV, VON DREIFUS D, MOREIRA MGC, ELIEL GSN, YEH CH, CHIU PW, PIMENTA MA, MALARD LM, DE PAULA AM
  • 作者关键词:   graphene, twisted bilayer, luminescence, femtosecond excitation
  • 出版物名称:   JOURNAL OF PHYSICSCONDENSED MATTER
  • ISSN:   0953-8984 EI 1361-648X
  • 通讯作者地址:   Univ Fed Minas Gerais
  • 被引频次:   1
  • DOI:   10.1088/1361-648X/aab64b
  • 出版年:   2018

▎ 摘  要

We report on photoluminescence emission imaging by femtosecond laser excitation on twisted bilayer graphene samples. The emission images are obtained by tuning the excitation laser energies in the near infrared region. We demonstrate an increase of the photoluminescence emission at excitation energies that depends on the bilayer twist angle. The results show a peak for the light emission when the excitation is in resonance with transitions at the van Hove singularities in the electronic density of states. We measured the photoluminescence excitation peak position and width for samples with various twist angles showing resonances in the energy range of 1.2 to 1.7 eV.