The synthesis of ReS2 flakes and its application in photodetectors
Abstract ReS2 is attracting much attention because of its stable trion state. This kind of stable trion state arises on account of weak interlayer coupling as well as anisotropic crystal structure. In this research, we have synthesized ReS2 flakes successfully by using chemical vapor deposition (CVD) method. Stable ionic states in hexagonal wafers are observed by photoluminescence spectroscopy (PL). This substance is stable at room temperature. The HRTEM image from the single ReS2 hexagon reveals that the individual hexagon is single crystal. EDS spectroscopy indicates the purity of the synthesized product. We find that the Re and S atoms ratio in pure ReS2 is 1:2. Then we fabricate a photo detector on individual ReS2 flakes and test its performance. We compare the photocurrent in dark current and under a 500 nm incident light for two media (air and 100 ppm H2). Emission current increases from 1.15 μA to 1.67 μA (forward) and from 7.9 μA to 13.8 μA (reverse). Therefore, the ReS2 hexagonal wafer is an ideal choice for stable and reliable room temperature optical gas sensor. And the material can also be used for fast switch.