Yong-Hong Zhao1,2, Feng Yang1,3, Jian Wang2, Hong Guo4, and Wei Ji3
1College of Physics and Electronic Engineering, Institute of Solid State Physics, Sichuan Normal University, Chengdu 610068, China
2Department of Physics and the Center of Theoretical and Computational Physics, The University of Hong Kong, Hong Kong, China
3Department of Physics, Renmin University of China, Beijing 100872, China
4Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China
5Centre for the Physics of Materials and Department of Physics, McGill University, 3600 rue University, Montreal PQ, Canada H3A 2T8
DOI:10.1038/srep08356 Publication Date: 13 February 2015
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 andWSe2 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% normallayer 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.