Atmospheric Pressure PVD Growth of Ultrathin SnSe, MoS₂, and SnS Films on ITO for High-Performance Photoelectrochemical Photodetectors

Electrochemical devices based on the interface between indium tin oxide (ITO) and nanomaterials have been widely applied in hydrogen production, photocatalysis, photodetectors, and biosensors. However, conventional fabrication methods such as coating, spin-coating, and printing usually form loose nanomaterials/ITO interfaces with large potential barriers, resulting in poor electronic transport properties. Herein, we have developed a universal atmospheric pressure tube-furnace physical vapor deposition (PVD) approach for the controllable growth of ultrathin SnSe, MoS₂, and SnS films directly on ITO substrates. The effects of the deposition temperature on the morphology, microstructure, and growth mechanism of SnSe are investigated. Owing to the formation of fine-grained ultrathin films with maximized interfacial contact to ITO, vertical charge extraction across the semiconductor/ITO interface is significantly enhanced, leading to a markedly improved photoelectrochemical photodetection performance. This work provides a controllable and scalable strategy for the direct integration of ultrathin semiconductor films with ITO electrodes, offering a general route toward high-performance electrochemical and photoelectrochemical devices.