Substrate control for large area continuous films of monolayer MoS₂by atmospheric pressure chemical vapor deposition

Abstract

Growing monolayer MoS2 films that are continuous with large domain sizes by chemical vapor deposition is one of the major challenges in 2D materials research at the moment. Here, we explore how atmospheric pressure CVD can be used to grow centimeter scale continuous films of monolayer MoS2 films directly on Si substrates with an oxide layer whilst also obtaining large domain sizes exceeding 20 μm within the films. This is achieved by orientating the growth substrate in a vertical position to improve the uniformity of precursor feed-stock compared to horizontally orientated growth substrates. This leads to continuous films of monolayer MoS2 over a significantly larger area without the need for low-pressure vacuum systems or volatile precursors. This provides important insights into novel approaches for maximizing domain sizes within MoS2 films, with concomitant large area uniform coverage.