Structural and optical characterization of rhenium disulfide grown by chemical vapor deposition

Flakes of rhenium disulfide, ReS 2 , were synthesized on SiO 2 /Si and sapphire substrates by atmospheric-pressure chemical vapor deposition using ReO 3 and sulfur powders as precursors, with the ReO 3 source and substrates placed inside a confined, closed-end inner quartz tube. The growth produced isolated flakes with triangular and irregular morphologies on both substrates. Raman spectroscopy resolved features corresponding to the 18 Raman-active modes of ReS 2 between 100 and 450 cm −1 , consistent with the vibrational fingerprint of the distorted 1 T structure. Photoluminescence measurements on SiO 2 /Si with 472.92 nm excitation revealed an emission peak near 1.58 eV, consistent with the excitonic emission energy reported for ReS 2 . For flakes grown on sapphire, 632.8 nm excitation was used to suppress the substrate background, yielding an emission peak at 1.53 eV, close to the SiO 2 /Si result.