Van der Waals Heteroepitaxy of Te Crystallites/2H-MoTe₂ Atomically Thin Films on GaAs Substrates by Using Metal-Organic Chemical-Vapor Deposition

Te crystallites/few atomic-layer MoTe₂ films grown on (100) GaAs substrates by using metal-organic chemical — vapor deposition (MOCVD) were investigated. MOCVD provides high-quality films, controllable film thickness, composition uniformity, and scalability to wafer scale size via the pyrolysis process of metal-organic sources. We observed several tens of nanometers of Te crystallites/three atomic layers 2H phase MoTe₂ on the GaAs substrates. This observation was confirmed by using Raman spectroscopy, X-ray photoemission spectroscopy (XPS), atomic force microscopy, cross-sectional scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. A two-dimensional transition-metal dichalcogenide deposited on GaAs by using the van der Waals epitaxy is a promising method for the development of future high-performance optoelectronic and electronic devices.