Oriented lateral growth of monolayer MoS2 mediated by highly-oriented MoO2 nanorods on sapphire†

Abstract

Two-dimensional (2D) transition metal chalcogenides (TMDs) have demonstrated immense potential and broad prospects in advancing the fields of next-generation optoelectronics, spintronics, valley electronics, and traditional electronics. In recent years, significant progress has been made in the growth research of TMDs through continuous optimization and innovation of various synthetic strategies. However, precisely controlling the growth conditions of materials, synthesizing high-quality 2D materials with a single domain structure, and achieving the desired shape and performance standards remain complex scientific challenges. Here, we report on the study of MoS₂ nucleation and growth habits by precisely controlling the ratio of molybdenum and sulfur sources during the growth process. Using pre-deposited highly oriented MoO₂ nanorods as templates, two preferentially oriented (0° or 60°) MoS₂ crystal domains were obtained on c-plane sapphire. Characterization using Raman spectroscopy, PL, XPS, and HRTEM reveals that the monolayer MoS₂ continuous film, grown using this templating method, possesses superior quality. Our work demonstrates a method for directional growth of 2D MoS₂ thin films using highly oriented 1D MoO₂ nanorods as templates and precursors, providing new insights into orientation control for epitaxial growth of 2D TMD materials.