Liquid metal-based synthesis of tin oxide nanosheets with application in transparent ultraviolet photodetectors

Abstract Liquid metal printing is an emergent strategy for growing ultrathin two-dimensional (2D) oxide materials, enabling their transfer from liquid metal surfaces onto substrates. In this study, liquid metal-printed 2D tin oxide (SnO) nanosheets with a large lateral size (>100 μm) and atomic-level thickness (<5 nm) were fabricated on SiO 2 /Si and glass substrates. Structural and spectroscopic analyses of the 2D SnO nanosheets confirmed the tetragonal SnO phase with characteristic valence states. By directly depositing the 2D SnO nanosheets on a glass substrate with interdigitated indium tin oxide electrodes, transparent ultraviolet (UV) photodetectors were fabricated. The obtained devices showed high transmittance (>85%) in the visible range and a pronounced photocurrent response under UV light irradiation, demonstrating the applicability of 2D SnO nanosheets to fabricate transparent UV photodetectors. These results highlight the potential of liquid metal printing as a simple, low-cost, and scalable route to obtain transparent oxide-based UV photodetectors and other optoelectronic devices.