• 文献标题:   Effect of Distance on Photoluminescence Quenching and Proximity-Induced Spin-Orbit Coupling in Graphene/WSe2 Heterostructures
  • 文献类型:   Article
  • 作  者:   YANG BW, MOLINA E, KIM J, BARROSO D, LOHMANN M, LIU YW, XU YD, WU RQ, BARTELS L, WATANABE K, TANIGUCHI T, SHI J
  • 作者关键词:   graphene, transition metal dichalcogenides tmds, proximity effect, photoluminescence pl, spinorbit coupling soc, interlayer distance
  • 出版物名称:   NANO LETTERS
  • ISSN:   1530-6984 EI 1530-6992
  • 通讯作者地址:   Univ Calif Riverside
  • 被引频次:   2
  • DOI:   10.1021/acs.nanolett.8b00691
  • 出版年:   2018

▎ 摘  要

Spin-orbit coupling (SOC) in graphene can be greatly enhanced by proximity coupling it to transition metal dichalcogenides (TMDs) such as WSe2. We find that the strength of the acquired SOC in graphene depends on the stacking order of the heterostructures when using hexagonal boron nitride (h-BN) as the capping layer, i.e., SiO2/graphene/WSe2/h-BN exhibiting stronger SOC than SiO2 /WSe2/graphene/h-BN. We utilize photoluminescence (PL) as an indicator to characterize the interaction between graphene and monolayer WSe2 grown by chemical vapor deposition. We observe much stronger PL quenching in the SiO2/graphene/WSe2/h-BN stack than in the SiO2 /WSe2/graphene/h-BN stack and, correspondingly, a much larger weak antilocalization (WAL) effect or stronger induced SOC in the former than in the latter. We attribute these two effects to the interlayer distance between graphene and WSe2, which depends on whether graphene is in immediate contact with h-BN. Our observations and hypothesis are further supported by first-principles calculations, which reveal a clear difference in the interlayer distance between graphene and WSe2 in these two stacks.