High-Speed and Low-Noise Photodetectors Based on Solution-Processed AgInS₂

Solution-processed chalcogenides have emerged as promising candidates for next-generation photovoltaics and photodetection, mainly benefiting from their facile fabrication, excellent stability, and tunable optoelectronic properties. However, most of the multicrystalline chalcogenide thin films suffer from poor charge transport properties and complicated trap states. In this work, we developed In-based chalcogenide thin films, i.e., AgInS2. The charge carrier dynamics of In-based chalcogenides was carefully evaluated, which showed relatively high charge carrier mobility, a longer lifetime, and reduced nonradiative recombination losses compared with their counterparts, AgSbS2 and AgBiS2. We also fabricated photodetector-based In-based chalcogenides and achieved extremely low dark current and noise, decent detectivity, ultrafast photoresponse, and superior device stability. Benefitting from these performance metrics, the optimized devices also demonstrated great potential for multiple applications, such as photoplethysmography, X-ray detection, and smog monitoring.