Investigation of Electrical and Optical Properties of Chemical Vapor Deposition Grown MoS2(1−x)Se2x

Alloy engineering has emerged as an effective strategy for tuning the optoelectronic properties of two‐dimensional transition‐metal dichalcogenides. To this aim, large‐area bilayer MoS 2(1− x ) Se 2 x alloys are synthesized on SiO 2 /Si substrate using a controlled chemical vapor deposition (CVD) technique, where the influence of several growth parameters are investigated. Raman and photoluminescence spectroscopic techniques are employed to investigate the systematic changes in the structural and optical properties of MoS 2(1− x ) Se 2 x alloys. Specifically, a 5% H 2 ‐mixing with the carrier gas (Ar) has been proven to be a successful strategy to obtain large‐area growth coverage and improved alloy formation. To evaluate the electronic performance of the MoS 2(1− x ) Se 2 x alloys, a field‐effect transistor (FET) is fabricated by wet‐transferring the CVD‐grown film on photomicrographed electrodes. The FET shows n‐type transfer characteristics with a high (≈10 3 ) on‐off ratio. Temperature‐dependent current–voltage measurements of the fabricated FET revealed activated conduction as the primary charge transport mechanism. Under white light illumination, the device exhibited an impressive three‐order magnitude enhancement in the drain current, reflecting a higher degree of photo‐generated charge carriers and efficient charge transport. These findings reveal that CVD‐grown MoS 2(1− x ) Se 2 x is a highly versatile material with tunable optoelectronic properties, making it a promising candidate for advanced transistor and photodetector applications.