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

Inorganic metal chalcogenides, such as Ag2S, are well-known for their high absorption coefficient, high carrier concentration, and excellent carrier transport properties. Ag2S exhibits strong light absorption spanning from ultraviolet (UV) to near infrared (NIR), making it highly promising for photoelectric applications. In this study, Ag2S 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 Ag2S-based photodetector was prepared and exhibited a broadband photoresponse ranging from 350 to 1200 nm, covering both UV and NIR regions. The semitransparent Ag2S 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.