Complementary growth of 2D transition metal dichalcogenide semiconductors on metal oxide interfaces

Abstract

A chemical vapor deposition (CVD) growth model is presented for a technique resulting in naturally formed 2D transition metal dichalcogenide (TMD)-based metal-oxide-semiconductor structures. The process is based on a standard CVD reaction involving a chalcogen and transition metal oxide-based precursor. Here however, a thin metal oxide layer formed on lithographically defined contacts composed of pure bulk transition metal serves as the precursor. The chalcogen reacts with the metal oxide, leading to the growth of highly crystalline films, which display strong luminescence, monolayer Raman signatures, and relatively large crystal domains. Raman spectroscopy and cross-sectional SEM studies provide insight into the characteristics of the metal oxide and its effect on the TMD growth. The TMD material migrates outward along the substrate while remaining connected to the lithographically defined contacts, offering a scalable path for producing as-grown, naturally contacted, two-dimensional material-based devices.