Thermal-Evaporated Ag₂S Thin-Film for Stacked Photodetectors toward High-Resolution Wavelength Measurement

Inorganic metal chalcogenides, such as Ag 2 S, are well-known for their high absorption coefficient, high carrier concentration, and excellent carrier transport properties. Ag 2 S exhibits strong light absorption spanning from ultraviolet (UV) to near infrared (NIR), making it highly promising for photoelectric applications. In this study, Ag 2 S thin films with good crystallinity and near-stoichiometric composition were prepared via the thermal evaporation process. These films demonstrated high absorption coefficient, excellent carrier mobility and high carrier concentration. The Ag 2 S-based photodetector was prepared and exhibited a broadband photoresponse ranging from 350 to 1200 nm, covering both UV and NIR regions. The semitransparent Ag 2 S photodetector was further developed and employed to consrtuct a high-resolution wavelength recognition system. Experimental results revealed an impressive wavelength measurement resolution of 1 nm, highlighting its potential for integration into miniature spectrometers.