Self-powered UV photodetectors based on CsPbCl3 nanowires enabled by the synergistic effect of acetate and lanthanide ion passivation

Abstract

Recently, photodetectors based on perovskite nanomaterials have attracted considerable attention in the visible spectral region owing to their large absorption coefficients, long diffusion lengths and high optical gains. However, the fabrication of self-powered visible-blind ultraviolet (UV) photodetectors is still challenging for the perovskite nanomaterials. This work developed the self-powered UV photodetector based on the Eu(AcO)3 promoted CsPbCl3 nanowires (NWs), enabled by the great separation efficiency of electron-hole pairs and high electron mobility of the one-dimentional (1D) morphology of perovskite materials. The perovskite CsPbCl3 NWs were synthesized by a modified hot-injection method with assistant of Eu(AcO)3 additive. As supported by the experimental investigations and DFT calculations, the adsorption of Eu3+ and AcO− ions to the surface of perovskite not only promotes the anisotropic growth of perovskite in (200) orientation, but also efficently passivates the halide defect of the perovskite nanomaterials. Moreover, the self-powered UV photodetector based on the Eu(AcO)3 promoted CsPbCl3 NWs displays a high responsivity of 398 mA W−1, detectivity up to 3.3 × 1011 Jones and fast response speed (24 ms) at 360 nm without external bias. The responsivity and detectivity of the device based on CsPbCl3 NWs are improved 8 and 205 times, comparing with the device based on bare CsPbCl3 NCs without passivation, respectively. In addition, the detectivity is comparable to some previous reports about perovskite NC-based UV photodetectors with additional bias. Our findings demonstrate the promising potential of 1D perovskite NWs for developing the next-generation self-powered UV photodetectors.