Synthesis and Application of AgBiS and AgS Nanoinks for the Production of IR Photodetectors.

Nanoinks composed of quantum dots (QDs) are applied in light-receiving devices and light-emitting devices such as solar cells and displays. However, since the most widely used QDs, PbS and CdS, are toxic and environmentally concerning, alternative materials need to be developed. We synthesized and analyzed Ag chalcogenide nanoparticles, including AgBiS and AgS nanoparticles, which are eco-friendly materials. AgBiS and AgS QD films were prepared by spin-coating nanoparticle solutions and subsequent heat treatment. The effects of the heat treatment on residual ligands and photoluminescence were determined by surface analysis. The photocurrent response of the AgBiS and AgS QD films was measured in the near-infrared region, and the effect of the heat treatment temperature was investigated. The results indicate that AgBiS and AgS are prospective materials for near-infrared photodetectors.