Infrared Photodetectors Based on Silver Chalcogenide Colloidal Quantum Dots

Infrared (IR) photodetectors play a crucial role in various applications, including autonomous driving, optical communication, and biomedical imaging. Silver chalcogenide colloidal quantum dots (CQDs), namely silver sulfide (Ag₂S), silver selenide (Ag₂Se) and silver telluride (Ag₂Te) have emerged as competitive materials for the next generation of IR photodetectors due to several advantages, such as tunable bandgap, solution processing ability, as well as their low-cost and environment-friendly syntheses. This review considers the synthesis methods and the optical properties of silver chalcogenide CQDs. It is discussed that how the performance of IR photodetectors based on silver chalcogenide CQDs can be improved by means of the ligand exchange; making heterostructures active layers that combine CQDs with metal halide perovskites, polymers, and silicon; optimization of interface transport layers, and by overall design of the device structure. Performance parameters such as responsivity and detectivity of photodetectors based on silver chalcogenide are compared, with those based on widely studied IR PbS and HgTe CQDs. Finally, existing challenges and prospects of the real-world applications of IR photodetectors based on silver chalcogenide CQDs are considered.