Controllable Synthesis of 2H-1T′ Mo_xRe_(1-x)S₂ Lateral Heterostructures and Their Tunable Optoelectronic Properties

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_xRe_(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_xRe_(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_xRe_(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_xRe_(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.