Centimeter-Scale Nearly Single-Crystal Monolayer MoS2 via Self-Limiting Vapor Deposition Epitaxy

Monolayer molybdenum disulfide (MoS2), a member of layered transition metal dichalcogenides (TMDCs), possesses a direct bandgap, high optical absorption, and prominent piezoelectricity, as well as has enjoyed a wide range of applications in electronics and optoelectronics. Most investigators have ubiquitously synthesized this material by using the chemical vaporization deposition method. Here we have discovered the self-limiting vapor deposition epitaxy (SLVDE), which governs the synthesis of integrated centimeter-scale nearly single-crystal monolayer MoS2 films with high experimental repeatabilities. This mechanism (a) utilizes the van der Waals force that induces the epitaxy and (b) differentiates magnitudes of saturated source-material vapor pressures that avoid undesirable pyramid-like structures. The energy peak of the photoluminescence hump located at 1.89 eV (near the theoretical-value 1.90 eV) and a high average hole mobility valued as 317.2 cm2 V–1 s–1 demonstrate high optoelectronic quality of t...