• 文献标题:   Building Large-Domain Twisted Bilayer Graphene with van Hove Singularity
  • 文献类型:   Article
  • 作  者:   TAN ZJ, YIN J, CHEN C, WANG H, LIN L, SUN LZ, WU JX, SUN X, YANG HF, CHEN YL, PENG HL, LIU ZF
  • 作者关键词:   twisted bilayer graphene, interlayer coupling, van hove singularity, photocurrent enhancement
  • 出版物名称:   ACS Nano
  • ISSN:   1936-0851 EI 1936-086X
  • 通讯作者地址:   Peking Univ
  • 被引频次:   15
  • DOI:   10.1021/acsnano.6b02046
  • 出版年:   2016

▎ 摘  要

Twisted bilayer graphene (tBLG) with van Hove Singularity (VHS) has exhibited novel twist-angle-dependent chemical and physical phenomena. However, scalable production of high-quality tBLG is still in its infancy, especially lacking the angle controlled preparation methods. Here, we report a facile approach to prepare tBLG with large domain sizes (>100 mu m) and controlled twist angles by a clean layer-by-layer transfer of two constituent graphene monolayers. The whole process without interfacial polymer contamination in two monolayers guarantees the interlayer interaction of the pi-bond electrons, which gives rise to the existence of minigaps in electronic structures and the consequent formation of VHSs in density of state. Such perturbation on band structure was directly observed by angle-resolved photoemission spectroscopy with submicrometer spatial resolution (micro-ARPES). The VHSs lead to a strong light-matter interaction and thus introduce similar to 20-fold enhanced intensity of Raman G-band, which is a characteristic of high-quality tBLG. The as-prepared tBLG with strong light matter interaction was further fabricated into high-performance photodetectors with selectively enhanced photocurrent generation (up to similar to 6 times compared with monolayer in our device).