Comparison of the MOCVD growth and properties of wafer-scale transition metal dichalcogenide epitaxial monolayers
Tanushree H. Choudhury, Nicholas Trainor, Chen Chen, Mikhail Chubarov, Saiphaneendra Bachu, Kasra Momeni, James Spencer Lundh, Danielle Reifsnyder Hickey, Tianyi Zhang, Amritanand Sebastian, Haoyue Zhu, Baokun Song, Yueli Chen, Benjamin Huet, Anushka Bansal, Sukwon Choi, Nasim Alem, Mauricio Terrones, Deep Jariwala, Saptarshi Das, Joan M. Redwing
Abstract
Abstract Epitaxial growth of transition metal dichalcogenides (TMDs) by metalorganic chemical vapor deposition is a promising method for wafer-scale synthesis of monolayer films. This study focuses on a comparison of the epitaxial growth of MoS 2 , WS 2 , and WSe 2 monolayers on 2 inch c-plane sapphire substrates using a cold-wall reactor with metal hexacarbonyl and hydride chalcogen sources. Uniform thermofluidic conditions enabled a comparative analysis of nucleation density, domain size, and lateral growth rate across TMD compounds, shedding light on the impact of TMD chemistry on epitaxial growth. Despite the use of chemically analogous precursors such as Mo(CO) 6 or W(CO) 6 and H 2 S or H 2 Se, significant differences in growth behavior are observed. Comprehensive structural, optical, and transport characterizations provide insights into sulfur versus selenium-based TMDs, advancing the understanding of optimized growth conditions for these emerging materials.