Self-powered CsPbBr3 nanowire photodetector with a vertical structure

Single crystal halide perovskite nanowires (NWs) have attracted much attention for use in high-performance photodetectors (PDs) due to their high photoluminescence quantum yields, large carrier mobilities, and long carrier diffusion lengths. So far, most high-performance NW PDs are fabricated based on individual or aligned NWs which require complicated preparation processing. Furthermore, it is challenging for these NW PDs to possess self-powered operation characteristics. Here, we report self-powered perovskite NW PDs with a vertical p-i-n structure in which the CsPbBr3 NWs are grown by a combination of solution-phase and halide exchange processes. Before depositing the hole selective layer, poly(methyl methacrylate) is coated on perovskite NW film to fill the internal voids, which passivates surfaces of perovskite NWs and reduces the dark current. Our optimized CsPbBr3 NW PDs show dark current density as low as 4.0 nA cm−2 and photocurrent density as high as 22.9 mA cm−2 under a 473 nm laser illumination with intensity of 641 mW cm−2, leading to a high linear dynamic range of 135 dB. In addition, our perovskite NW PDs display highly self-powered performance with ultrohigh on/off ratios of above 106, responsivity of up to 0.3 A W−1 and detectivity of up to 1 × 1013 Jones at 0 V.