Controllable Synthesis of 2H-1T' Mo_x Re_(1- _x ₎ S₂ Lateral Heterostructures and Their Tunable Optoelectronic Properties.

Abstract

Constructing heterostructures and doping are valid ways to improve the optoelectronic properties of transition metal dichalcogenides (TMDs) and optimize the performance of TMDs-based photodetectors. Compared with transfer techniques, chemical vapor deposition (CVD) has higher efficiency in preparing heterostructures. As for the one-step CVD growth of heterostructures, cross-contamination between the two materials may occur during the growth process, which may provide the possibility of one-step simultaneous realization of controllable doping and formation of alloy-based heterostructures by finely tuning the growth dynamics. Here, 2H-1T' Mo_x Re_(1- _x ₎ S₂ alloy-to-alloy lateral heterostructures are synthesized through this one-step CVD growth method, utilizing the cross-contamination and different growth temperatures of the two alloys. Due to the doping of a small amount of Re atoms in 2H MoS₂ , 2H Mo_x Re_(1- _x ₎ S₂ has a high response rejection ratio in the solar-blind ultraviolet (SBUV) region and exhibits a positive photoconductive (PPC) effect. While the 1T' Mo_x Re_(1- _x ₎ S₂ formed by heavily doping Mo atoms into 1T' ReS₂ will produce a negative photoconductivity (NPC) effect under UV laser irradiation. The optoelectronic property of 2H-1T' Mo_x Re_(1- _x ₎ S₂ -based heterostructures can be modulated by gate voltage. These findings are expected to expand the functionality of traditional optoelectronic devices and have potential applications in optoelectronic logic devices.