Low-Noise and Large-Linear-Dynamic-Range Photodetectors Based on Hybrid-Perovskite Thin-Single-Crystals

Organic-inorganic halide perovskites are promising photodetector materials due to their strong absorption, large carrier mobility, and easily tunable bandgap. Up to now, perovskite photodetectors are mainly based on polycrystalline thin films, which have some undesired properties such as large defective grain boundaries hindering the further improvement of the detector performance. Here, perovskite thin-single-crystal (TSC) photodetectors are fabricated with a vertical p-i-n structure. Due to the absence of grain-boundaries, the trap densities of TSCs are 10-100 folds lower than that of polycrystalline thin films. The photodetectors based on CH₃ NH₃ PbBr₃ and CH₃ NH₃ PbI₃ TSCs show low noise of 1-2 fA Hz^-1/2 , yielding a high specific detectivity of 1.5 × 10¹³ cm Hz^1/2 W^-1 . The absence of grain boundaries reduces charge recombination and enables a linear response under strong light, superior to polycrystalline photodetectors. The CH₃ NH₃ PbBr₃ photodetectors show a linear response to green light from 0.35 pW cm^-2 to 2.1 W cm^-2 , corresponding to a linear dynamic range of 256 dB.