A monolithically integrated near-infrared imager with crystallization- and oxidation-modulated tin-lead perovskites

The fast crystallization and facile oxidation of Sn²⁺ of tin-lead (Sn-Pb) perovskites are the biggest challenges for their applications in high-performance near-infrared (NIR) photodetectors and imagers. Here, we introduce a multifunctional diphenyl sulfoxide (DPSO) molecule into perovskite precursor ink to response these issues by revealing its strong binding interactions with the precursor species. The regulated perovskite film exhibits a dense morphology, reduced defect density and prolonged carrier diffusion length. The manufactured self-powered photodetector realizes a spectral response of 300-1100 nm, dark current density of 4.7 × 10^-8 mA cm^-2, peak responsivity of 0.49 A W^-1 and specific detectivity of 1.20 × 10¹² Jones in NIR region (780-1100 nm), -3 dB bandwidth of 11.4 MHz, linear dynamic range of 174 dB, and ultrafast rise/fall time of 14.2/17.1 ns, respectively. We demonstrate a 64 × 64 NIR imager with an impressive spatial resolution of 1.32 lp mm^-1 by monolithically integrating the photodetector with a commercial thin-film transistor readout circuit.