Growth of 2D MoS2 and MoSe2 layers for photodetector application

Abstract

We have grown a few layers MoS2 and MoSe2 on Si (100) substrates using a chemical vapor deposition (CVD) technique at different approaches and growth temperatures. Structural, surface morphology and electronic properties were investigated by Raman spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy (XPS). The MoS2 thin films were grown using three-zone CVD system by employing the MoO3 and sulfur powder precursors. We have obtained characteristics E12g and A1g Raman modes of MoS2 peaks and the separation between these two modes revealed the formation of a 2-monolayer of MoS2 on Si (100) substrate. The triangular morphology of MoS2 layer with a thickness of ∼1.4 nm i.e. nearly 2-monolayer was deduced by atomic force microscopy. Similarly, a few layers of MoSe2 were grown on Si (100) by selenization of Mo-coated Si (100) and 2H-MoSe2 characteristics Raman peaks were obtained. The XPS analysis revealed the formation of pure MoS2 and MoSe2 thin films on Si (100) substrates. The two-dimensional materials on Si (100) can be used for broadband photodetector applications.