Continuously tunable electronic structure of transition metal dichalcogenides superlattices

Yong-Hong Zhao; Feng Yang; Jian Wang; Hong Guo; Wei Ji

doi:10.1038/srep08356

Continuously tunable electronic structure of transition metal dichalcogenides superlattices

Sci Rep. 2015 Feb 13:5:8356. doi: 10.1038/srep08356.

Authors

Yong-Hong Zhao¹, Feng Yang², Jian Wang³, Hong Guo⁴, Wei Ji⁵

Affiliations

¹ 1] College of Physics and Electronic Engineering, Institute of Solid State Physics, Sichuan Normal University, Chengdu 610068, China [2] Department of Physics and the Center of Theoretical and Computational Physics, The University of Hong Kong, Hong Kong, China.
² 1] College of Physics and Electronic Engineering, Institute of Solid State Physics, Sichuan Normal University, Chengdu 610068, China [2] Department of Physics, Renmin University of China, Beijing 100872, China [3] Beijing Key Laboratory of Optoelectronic Functional Materials &Micro-nano Devices, Renmin University of China, Beijing 100872, China.
³ Department of Physics and the Center of Theoretical and Computational Physics, The University of Hong Kong, Hong Kong, China.
⁴ Centre for the Physics of Materials and Department of Physics, McGill University, 3600 rue University, Montreal PQ, Canada H3A 2T8.
⁵ 1] Department of Physics, Renmin University of China, Beijing 100872, China [2] Beijing Key Laboratory of Optoelectronic Functional Materials &Micro-nano Devices, Renmin University of China, Beijing 100872, China.

Abstract

Two dimensional transition metal dichalcogenides have very exciting properties for optoelectronic applications. In this work we theoretically investigate and predict that superlattices comprised of MoS2 and WSe2 multilayers possess continuously tunable electronic structure with direct bandgaps. The tunability is controlled by the thickness ratio of MoS2 versus WSe2 of the superlattice. When this ratio goes from 1:2 to 5:1, the dominant K-K direct bandgap is continuously tuned from 0.14 eV to 0.5 eV. The gap stays direct against -0.6% to 2% in-layer strain and up to -4.3% normal-layer compressive strain. The valance and conduction bands are spatially separated. These robust properties suggest that MoS2 and WSe2 multilayer superlattice should be a promising material for infrared optoelectronics.