Fabrication of a 940 nm RuS2 Photodetector via Post-Sulfurization of Ru Thin Film Grown by Atomic Layer Deposition

In this study, we report RuS2 thin films fabricated by atomic layer deposition (ALD) of Ru thin film followed by a post-sulfurization process. The chemical states, surface morphologies, and electrical properties of RuS2 films were investigated with respect to Ru film thickness through several analyses such as SEM, TEM, and XRD. Furthermore, to compare the surface morphologies of ALD, RuS2 was also synthesized using physical vapor deposition (PVD) Ru films, and the influence of metallic Ru surface morphology before sulfurization and its reaction with H2S were discussed. We fabricated RuS2 940 nm photodetector with metal-semiconductor-metal structured electrodes and evaluated optical properties. Our results suggest that RuS2 films could be a potential candidate material for 940 nm photodetectors.