Room-Temperature High-Detectivity Flexible Near-Infrared Photodetectors with Chalcogenide Silver Telluride Nanoparticles.

Herein, flexible near-infrared (NIR) photodetectors were prepared using silver telluride (Ag 5 Te 3 ) nanoparticles (NPs) for optoelectronic applications. For the main channel materials of the photodetectors, Ag 5 Te 3 NPs were used, which were synthesized in an aqueous solution. Moreover, Ag 5 Te 3 thin films were successfully fabricated on plastic substrates at 150 °C using redistributed Ag 5 Te 3 NPs in aqueous inks. The crystal structure, chemistry, and optoelectronic properties of the synthesized photodetectors were studied. The fabricated flexible Ag 5 Te 3 -based photodetectors achieved a detectivity of 6.27 × 10 9 cm Hz 1/2 W -1 (>10 9 ) at room temperature under ∼0.35% compressive and tensile strains. The obtained detectivity value exceeds those of two-dimensional inorganic layered material phototransistors-such as MoS 2 -or commercial thermistor bolometers at room temperature (∼10 9 ). Furthermore, the proposed novel method for the synthesis of Ag 5 Te 3 thin films on plastic substrates can be applied to other Ag 5 Te 3 -based applications in the future.