Synthesis of Rhenium-Doped Molybdenum Sulfide by Atmospheric Pressure Chemical Vapor Deposition (CVD) for a High-Performance Photodetector

Abstract

Two-dimensional layered materials have attracted tremendous attention as photodetectors due to their fascinating features, including comprehensive coverage of band gaps, high potential in new-generation electronic devices, mechanical flexibility, and sensitive light-mass interaction. Currently, graphene and transition-metal dichalcogenides (TMDCs) are the most attractive active materials for constructing photodetectors. A growing number of emerging TMDCs applied in photodetectors bring up opportunities in the direct band gap independence with thickness. This study demonstrated for the first time a photodetector based on a few-layer RexMo1-xS2, which was grown by chemical vapor deposition (CVD) under atmospheric pressure. The detailed material characterizations were performed using Raman spectroscopy, photoluminescence, and X-ray photoelectron spectroscopy (XPS) on an as-grown few-layer RexMo1-xS2. The results show that both MoS2and ReS2peaks appear in the RexMo1-xS2Raman diagram. RexMo1-xS2is observed to emit light at a wavelength of 716.8 nm. The electronic band structure of the few layers of RexMo1-xS2calculated using the first-principles theory suggests that the band gap of RexMo1-xS2is larger than that of ReS2and smaller than that of MoS2, which is consistent with the photoluminescence results. The thermal stability of the few layers of RexMo1-xS2was evaluated using Raman temperature measurements. It is found that the thermal stability of RexMo1-xS2is close to those of pure ReS2and MoS2. The fabricated RexMo1-xS2photodetector shows a high response rate of 7.46 A W-1under 365 nm illumination, offering a competitive performance to the devices based on TMDCs and graphenes. This study unambiguously distinguishes RexMo1-xS2as a future candidate in electronics and optoelectronics.