过渡金属二硫属化物超晶格的连续可调电子结构

Continuously tunable electronic structure of transition metal dichalcogenides superlattices.

作者信息

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

机构信息

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.

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.

出版信息

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

DOI:10.1038/srep08356

PMID:25677917

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4326700/

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.

摘要

二维过渡金属二硫属化物在光电子应用方面具有非常令人兴奋的特性。在这项工作中，我们从理论上进行了研究并预测，由MoS2和WSe2多层组成的超晶格具有直接带隙且电子结构可连续调谐。这种可调谐性由超晶格中MoS2与WSe2的厚度比控制。当该比例从1:2变为5:1时，占主导的K-K直接带隙从0.14电子伏特连续调谐至0.5电子伏特。在面内应变达到-0.6%至2%以及垂直层压缩应变达到-4.3%时，该带隙仍保持直接带隙特性。价带和导带在空间上是分离的。这些稳健的特性表明，MoS2和WSe2多层超晶格应该是一种很有前景的红外光电子材料。