Thermal vapor sulfurization of molybdenum layers

Abstract

Sulfurization of molybdenum layers is a promising route for obtaining large-scale and high-quality transition metal dichalcogenides. Here we describe the synthesis of continuous and homogeneous MoS2 in the centimeter scale by the thermal vapor sulfurization of pre-deposited molybdenum precursors on SiO2. Metallic molybdenum as well as MoO3 were used as precursors while the sulfurization was performed by chemical vapor deposition. A multi-technique characterization was employed to fully describe the deposition of molybdenum as well as its sulfurization. Thus, Raman spectroscopy, X-ray and ultra-violet photoelectron spectroscopies as well as scanning electron and atomic force microscopies indicated that the molybdenum layers were completely transformed in MoS2. The samples were homogeneous in the centimeter scale and quite flat with a root mean square roughness of 1.4 Å. Furthermore, its work function was 4.1 eV.