Synthesis of WS2 crystals by the chemical vapor deposition (CVD) method on a SiO2 substrate

Abstract

The synthesis and characterization of WS2 single crystals grown by chemical vapor deposition (CVD) method thru sulfurization of tungsten oxide thin layer on quartz substrate was studied. Synthesis of WS2 was carried out at 800-1000 °C in CVD system. The sulphur vapor is transported by argon gas (500 sccm). Obtained WS2 single crystals characterized by optical microscope, Raman and photoluminescence analysis. Optical microscope analysis demonstrated that triangular WS2 domains with single phase crystal structure are formed. The thickness of WS2 is 6 layers, which determined by Raman spectroscopy. Photoluminescence spectroscopy is shown on Fig. 20, which revealed a strong peak between 600-660 nm, typically for a monolayer WS2 crystal, where the band gap is equal to 1.96 eV.