• 文献标题:   Band Alignment in WSe2-Graphene Heterostructures
  • 文献类型:   Article
  • 作  者:   KIM K, LARENTIS S, FALLAHAZAD B, LEE K, XUE JM, DILLEN DC, CORBET CM, TUTUC E
  • 作者关键词:   tungsten diselenide, graphene, heterostructure, band offset, band gap
  • 出版物名称:   ACS NANO
  • ISSN:   1936-0851 EI 1936-086X
  • 通讯作者地址:   Univ Texas Austin
  • 被引频次:   65
  • DOI:   10.1021/acsnano.5b01114
  • 出版年:   2015

▎ 摘  要

Using different types of WSe2 and graphene-based heterostructures, we experimentally determine the offset between the graphene neutrality point and the WSe2 conduction and valence band edges, as well as the WSe2 dielectric constant along the c-axis. In a first heterostructure, consisting of WSe2-on-graphene, we use the WSe2 layer as the top dielectric in dual-gated graphene field-effect transistors to determine the WSe2 capacitance as a function of thickness, and the WSe2 dielectric constant along the c-axis. In a second heterostructure consisting of graphene-on-WSe2, the lateral electron transport shows ambipolar behavior characteristic of graphene combined with a conductivity saturation at sufficiently high positive (negative) gate bias, associated with carrier population of the conduction (valence) band in WSe2. By combining the experimental results from both heterostructures, we determine the band offset between the graphene charge neutrality point, and the WSe2 conduction and valence band edges.