Centimeter-Sized Stable Zero-Dimensional Cs3Bi2I9 Single Crystal for Mid-Infrared Lead-Free Perovskite Photodetector

The detection of broadband spectroscopy is a huge challenge for modern optoelectronics, especially for extremely high- or low-energy photons. For metal halide perovskites significant progress has been made in high-energy photons such as X-rays, but there is little exploration of the perovskites in the high-performance detection of low-energy photons, especially mid- or far-infrared photons. Most infrared photodetectors suffer large dark currents, and perovskite photodetectors’ performances are significantly limited by ion migration. Here, a facile solution evaporation method is developed to grow a centimeter-scale zero-dimensional (0D), lead-free perovskite Cs3Bi2I9 single crystal for high-performance mid-infrared photodetectors with ultralow dark current drifts. The 0D Cs3Bi2I9 perovskite single crystal (PSC) photodetector shows an ultralow dark current drift (1.67 × 10–17 A cm–2 V–1 s–1, 9 orders of magnitude smaller than that of MAPbI3) and ultralow power consumption (smaller than 1 pA at 1 V bias) for greatly inhibited ion migration. The photodetector achieves effective photodetection from the ultraviolet to the mid-infrared (from 343 to 4000 nm) at room temperature based on the photoelectric and photobolometric effects with the best responsivity of 3.15 mA/W and detectivity of 8.7 × 108 jones at the wavelength of 343 nm at 0.033 mW/cm2. This work opens a door for low-dimensional perovskite-based mid-infrared detectors and provides a new path for the development of infrared perovskite photonics.