Direct Growth of Moiré Semiconductor Superlattices via Chemical Vapor Deposition

Transition‑metal dichalcogenides exhibit layer‑tunable band gaps, strong visible‑range absorption, and direct‑gap monolayers; their heterostructures can host moiré excitons, positioning TMDs for beyond‑CMOS optoelectronics. A central obstacle is wafer‑scale, transfer‑free growth of device‑grade monolayers and heterostructures directly on CMOS‑compatible substrates: polymer‑assisted film transfer introduces contamination, wrinkles, and defects that degrade electronic and optical performance. We develop advanced chemical‑vapor‑deposition routes targeting monolayer MoS₂/WS₂ heterostructures on hexagonal boron nitride substrates. As a first step, we demonstrate direct growth of monolayer WS₂ on SiO₂ and on hBN. Photoluminescence measurements reveal an overall PL‑intensity enhancement and a reduced trion population for WS₂ on hBN relative to SiO₂/Si, consistent with suppressed charge disorder and modified dielectric screening by hBN. Ongoing work optimizes MoS₂/WS₂ stacking and growth kinetics to control substrate‑dependent photophysics and to engineer large‑area moiré superlattices on hBN, enabling quantum‑light emission and advancing quantum optoelectronic platforms.