A Near-Infrared Imager Based on Oxidation-Suppressed Tin–Lead Perovskites

Abstract Tin–lead perovskites have emerged as promising materials for near-infrared (NIR) photodetectors (PDs) due to their tunable bandgap, excellent optoelectronic properties, and low-cost fabrication processes. However, the susceptibility of Sn2+ to oxidation and its rapid crystallization lead to numerous defects in the perovskite films, limiting the photoelectric performance and stability of perovskite PDs. Here, we introduce Nicotinohydrazide (NH) as a multifunctional additive to establish a multidentate chelation structure within tin–lead perovskites, improving the antioxidant capacity and crystallization quality of the perovskite film. Consequently, the perovskite PDs achieve excellent performance, including a low dark current of 2.58 × 10–11 A, a high external quantum efficiency of 76.9% at 850 nm, and remarkable stability, retaining 95.3% of the initial photocurrent after 2400 h of storage under a N2 atmosphere for unencapsulated devices. To realize their application in NIR imaging, we monolithically integrated the perovskite PDs with a 64 × 64 thin-film transistor (TFT) backplane. The imager demonstrates clear and accurate imaging capabilities with a high spatial resolution of 5.52 lp/mm, as evaluated by the slanted-edge method, enabling its potential application in intelligent imaging systems.