Synthesis of multiphase MoS ₂ heterostructures using temperature-controlled plasma-sulfurization for photodetector applications

Two-dimensional (2D) materials exhibit outstanding performance in photodetectors because of their excellent optical and electronic properties. Specifically, 2D-MoS₂, a transition metal dichalcogenide, is a prominent candidate for flexible and portable photodetectors based on its inherent phase-dependent tunable optical band gap properties. This research focused on creating high-performance photodetectors by carefully arranging out-of-plane 2D heterostructures. The process involved stacking different phases of MoS₂ (1T and 2H) using controlled temperature during plasma-enhanced chemical vapor deposition. Among the various phase combinations, the best photocurrent response was obtained for the 1T/2H-MoS₂ heterostructure, which exhibited an approximately two-fold higher photocurrent than the 2H/1T-MoS₂ heterostructure and 2H/2H-MoS₂ monostructure. The 1T/2H-MoS₂ heterostructure exhibited a higher photoresponse than the monostructured MoS₂ of the same thickness (1T/1T- and 2H/2H-MoS₂, respectively). The effect of the stacking sequences of different phases was examined, and their photoperformances were investigated. This study demonstrates that phase engineering in 2D-MoS₂ van der Waals heterostructures has significant potential for developing high-performance photodetectors.