ELECTRONIC AND OPTOELECTRONIC PROPERTIES OF TWO-DIMENSIONAL TRANSITION METAL DICHALCOGENIDES AND THEIR HETEROSTRUCTURES

Abstract

Layered transition metal dichalcogenides are a category of semiconductor with layer-dependent electronic structures in the two dimensional limit. We first investigated the effect of air to the performance of WSe2 transistors and explored the feasibility of efficient P-doping by the adsorption of ozone. The layer-dependent band structures together with the diversity of different chalcogenides provide more possibility to create structures with desirable properties by hetero-stacking. In our work, we took advantage of type II band alignment between MoS2 and WSe2 and fabricated heterojunctions showing excellent rectification and solar energy conversion efficiency. Given the remarkable excitonic effects in monolayers, we further designed a light emitting WS2/BN/Graphite hetero-structure with high quantum efficiency, where the injection of carriers are realized by tunneling. Our results support that two dimensional TMDs are of great potential for future electronics and optoelectronics.