Wafer-Scale Epitaxial 1T', 1T'-2H Mixed, and 2H Phases MoTe2 Thin Films Grown by Metal-Organic Chemical Vapor Deposition

2D materials beyond molybdenum disulfide such as molybdenum ditelluride (MoTe2) have attracted increasing attention because of their distinctive properties, such as phase-engineered, relatively narrow direct bandgap of 1.0-1.1 eV and superior carrier transport. However, a wafer-scale synthesis process is required for achieving practical applications in next-generation electronic devices using MoTe2 thin films. Herein, the direct growth of atomically thin 1T', 1T'-2H mixed, and 2H phases MoTe2 films on a 4 in. SiO2/Si wafer with high spatial uniformity (approximate to 96%) via metal-organic vapor phase deposition is reported. Furthermore, the wafer-scale phase engineering of few-layer MoTe2 film is investigated by controlling the H-2 molar flow rate. While the use of a low H-2 molar flow rate results in 1T' and 1T'-2H mixed phase MoTe2 films, 2H phase MoTe2 films are obtained at a high H-2 molar flow rate. Field-effect transistors fabricated with the prepared 2H and 1T' phases MoTe2 channels reveal p-type semiconductor and semimetal properties, respectively. This work demonstrates the potential for reliable wafer-scale production of 1T' and 2H phases MoTe2 thin films employing the H-2 molar flow rate-controlled phase tunable method for practical applications in next-generation electronic devices as a p-type semiconductor and Wyle semimetal.