High electron mobility, quantum Hall effect and anomalous optical response in atomically thin InSe

Autor: Bandurin, Denis A., Tyurnina, Anastasia V., Yu, Geliang L., Mishchenko, Artem, Morozov, Sergey V., Kumar, Roshan Krishna, Gorbachev, Roman V., Kudrynskyi, Zakhar R., Pezzini, Sergio, Kovalyuk, Zakhar D., Zeitler, Uli, Novoselov, Konstantin S., Eaves, Laurence, Grigorieva, Irina V., Fal'Ko, Vladimir I., Geim, Andre K., Cao, Yang
Jazyk: angličtina
Rok vydání: 2017
Předmět:
ISSN: 1748-3387
1748-3395
Popis: © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. A decade of intense research on two-dimensional (2D) atomic crystals has revealed that their properties can differ greatly from those of the parent compound. These differences are governed by changes in the band structure due to quantum confinement and are most profound if the underlying lattice symmetry changes. Here we report a high-quality 2D electron gas in few-layer InSe encapsulated in hexagonal boron nitride under an inert atmosphere. Carrier mobilities are found to exceed 103 cm2 V-1 s-1 and 104 cm2 V-1 s-1 at room and liquid-helium temperatures, respectively, allowing the observation of the fully developed quantum Hall effect. The conduction electrons occupy a single 2D subband and have a small effective mass. Photoluminescence spectroscopy reveals that the bandgap increases by more than 0.5eV with decreasing the thickness from bulk to bilayer InSe. The band-edge optical response vanishes in monolayer InSe, which is attributed to the monolayer's mirror-plane symmetry. Encapsulated 2D InSe expands the family of graphene-like semiconductors and, in terms of quality, is competitive with atomically thin dichalcogenides and black phosphorus.
Databáze: OpenAIRE
Externí odkaz: