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

Abstract

Herein, flexible near-infrared (NIR) photodetectors were prepared using silver telluride (Ag₅Te₃) nanoparticles (NPs) for optoelectronic applications. For the main channel materials of the photodetectors, Ag₅Te₃ NPs were used, which were synthesized in an aqueous solution. Moreover, Ag₅Te₃ thin films were successfully fabricated on plastic substrates at 150 °C using redistributed Ag₅Te₃ NPs in aqueous inks. The crystal structure, chemistry, and optoelectronic properties of the synthesized photodetectors were studied. The fabricated flexible Ag₅Te₃-based photodetectors achieved a detectivity of 6.27 × 10⁹ cm Hz^1/2 W^-1 (>10⁹) 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 MoS₂-or commercial thermistor bolometers at room temperature (∼10⁹). Furthermore, the proposed novel method for the synthesis of Ag₅Te₃ thin films on plastic substrates can be applied to other Ag₅Te₃-based applications in the future.