Growth of Single-Layer MoS2 by Chemical Vapor Deposition on sapphire substrate

Abstract

Single-layer molybdenum disulfide (MoS2) has attracted a significant amount of interest owing to its excellent electrical, optical, and mechanical properties. In this paper, we study that the effects of the distance between the molybdenum source and substrate as well as the substrate angle on the morphology, size, and structure of MoS2 films grown from molybdenum trioxide (MoO3) sulfide on sapphire substrates via the Chemical Vapor Deposition (CVD) by using Scanning electron microscopy (SEM), Raman spectra and Photoluminescence spectra (PL). On the results show that the distance between the substrate and molybdenum source affects the controllable growth of MoS2 films. When the substrate is too close to the molybdenum source, it results in increasing amount of non-reduced MoO3 particles which were deposited on the substrate. When the distance between the substrate and molybdenum source is too large, only a small amount of MoS2 is deposited on the substrate. High-quality MoS2 films can be prepared when the molybdenum source and substrate are 9.5 cm apart. When the substrate is inclined 30° and placed downstream of the molybdenum source with a distance of 9.5 cm, the size of the prepared single-layer MoS2 is approximately 100 μm, which is greater than that of MoS2 prepared on the horizontal face-up substrate.