MgO/ZnO microsphere bilayer structure towards enhancing the stability of the self-powered MAPbI3 perovskite photodetectors with high detectivity

In recent years, organic-inorganic hybrid perovskite photodetectors (PDs) have been regarded as promising nextgeneration PDs. However, the commercialization of the perovskite PDs still faces significant challenges, one of which is the poor stability. Herein, we demonstrate MgO/ZnO microsphere (MS) bilayer structure for improving the device stability with high detectivity. In this MgO/ZnO MS bilayer, ZnO MS array scaffold can facilitate the penetration of perovskite into nano-arrays and benefits the light harvest efficiency due to the special microsphere array structure, which behaves a big gap between aligned nanostructures. MgO passivates the interface between ZnO and perovskite, enhancing the device stability and promoting the carrier transport. Finally, our PDs with the bilayer structure exhibit high performance with the on/off ratio of up to more than 7.0 x 10(4), the linear dynamic range of 87.7 dB, and the detectivity of 1.5 x 10(12) Jones, all of which are better than those of the device without MgO. More importantly, the device with the bilayer structure shows better stability compared with the device without MgO. Under illumination with the optical power of 314 mW/cm(2), the photocurrent of the device with MgO shows almost no attenuation after continuous illumination for 30 min. In addition, after storing in air for 15 days, the performance of the device with MgO exhibits slight attenuation and the on/off ratio is still as high as 2.3 x 10(4), indicating that the device has good storage stability.