Heterojunction Enabled Room‐Temperature Self‐Powered AgBiS 2 Quantum Dots Photodetectors up to 2.3 µm

ABSTRACT The development of low‐cost, high‐performance, uncooled broadband photodetectors (PDs) is crucial for optical communication and imaging. However, achieving deep‐ultraviolet (DUV) to extended short‐wave infrared (eSWIR) detection in a single device remains challenging. Herein, a novel ultrabroadband Type‐II AgBiS 2 quantum dots (QDs)/In 0.75 Ga 0.25 As heterojunction is used as the photosensitive layer, significantly enhancing charge separation and transport, suppressing interface carrier recombination, and improving stability. Compared with the pristine AgBiS 2 QDs PDs, the self‐powered PDs based on this heterojunction exhibit a response from 0.3 to 2.3 µm, with responsivity of 1.66 A/W and detectivity of 2.64 × 10 12 Jones. They also show remarkable long‐term and operational stability, retaining 94.1% response after 20000 h storage and 96.7% after 10000 ON/OFF cycles. This PD enables broadband imaging without cryogenic cooling, showing great promise for practical applications. This work provides a new strategy for self‐powered ultrabroadband PDs (DUV‐eSWIR), opening up new opportunities for future optoelectronic systems.