Premium
Substrate Doping Effect and Unusually Large Angle van Hove Singularity Evolution in Twisted Bi‐ and Multilayer Graphene
Author(s) -
Peng Han,
Schröter Niels B. M.,
Yin Jianbo,
Wang Huan,
Chung TingFung,
Yang Haifeng,
Ekahana Sandy,
Liu Zhongkai,
Jiang Juan,
Yang Lexian,
Zhang Teng,
Chen Cheng,
Ni Heng,
Barinov Alexey,
Chen Yong P.,
Liu Zhongfan,
Peng Hailin,
Chen Yulin
Publication year - 2017
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201606741
Subject(s) - materials science , graphene , van hove singularity , bilayer graphene , fermi level , fermi energy , doping , optoelectronics , photoemission spectroscopy , band gap , substrate (aquarium) , condensed matter physics , nanotechnology , physics , x ray photoelectron spectroscopy , oceanography , nuclear magnetic resonance , quantum mechanics , geology , electron
Graphene has demonstrated great potential in new‐generation electronic applications due to its unique electronic properties such as large carrier Fermi velocity, ultrahigh carrier mobility, and high material stability. Interestingly, the electronic structures can be further engineered in multilayer graphene by the introduction of a twist angle between different layers to create van Hove singularities (vHSs) at adjustable binding energy. In this work, using angle‐resolved photoemission spectroscopy with sub‐micrometer spatial resolution, the band structures and their evolution are systematically studied with twist angle in bilayer and trilayer graphene sheets. A doping effect is directly observed in graphene multilayer system as well as vHSs in bilayer graphene over a wide range of twist angles (from 5° to 31°) with wide tunable energy range over 2 eV. In addition, the formation of multiple vHSs (at different binding energies) is also observed in trilayer graphene. The large tuning range of vHS binding energy in twisted multilayer graphene provides a promising material base for optoelectrical applications with broadband wavelength selectivity from the infrared to the ultraviolet regime, as demonstrated by an example application of wavelength selective photodetector.