TaS2 as a p-type Ohmic contact for monolayer SnSe and its device performance from ab initio simulations

Abstract

Monolayer (ML) SnSe has received significant attention in electronics and optoelectronics due to its high efficiency in electrostatic gating, high carrier mobility, and chemical stability and has been synthesized in various ways. In this study, we employed ab initio simulations to assess the contact performance of a van der Waals heterojunction formed by 2H-TaS₂ and SnSe monolayers. Our findings indicate that positive charge carriers can move freely from TaS₂ to SnSe due to the absence of a Schottky barrier at the interface and the presence of upward band-bending. Moreover, unlike conventional metal contacts the intrinsic nature of both ML SnSe and TaS₂ remains unchanged in the heterostructure. We also report the enhanced optical response observed in TaS₂/SnSe heterostructure compared to the free-standing monolayers. Following the recent synthesis of 2H-TaS₂/SnS superlattices, this study proposes the potential synthesis of ML SnSe in contact with TaS₂ with enhanced understanding of their interface properties.