Modulating the Quantum Efficiency of Sb2S3‐Based Photodiodes Based on Conventional and Inverted Structures

Abstract Antimony sulfide (Sb 2 S 3 ), a binary chalcogenide, has recently emerged as a promising candidate for photovoltaics due to its high absorption coefficient, facile processing, and lower toxicity. However, high‐performance photodiodes based on Sb 2 S 3 have not been achieved and systematically investigated. Herein, Sb 2 S 3 ‐based photodiodes based on conventional and inverted structures are developed, and their charge transport and spectral dependent quantum efficiency of these two types of devices are carefully modulated. After optimization, the conventional photodetectors achieve broadband responsivity up to 0.3 A W −1 , high specific detectivity of 1.25 × 10 12 Jones, and fast response speed of 6.4 µs with a small bias voltage of −0.5 V. On the other hand, the inverted devices exhibit imbalanced charge transport and color discrimination, which is promising for narrowband photodetection. These distinct device performances are highly dependent on the device architecture, which is crucial for designing efficient chalcogenide‐based optoelectronic devices.