Self-Powered and Flexible Photodetector with High Polarization Sensitivity Based on MAPbBr3-MAPbI3 Microwire Lateral Heterojunction

Assembling perovskites into heterojunctions is an effective approach to achieve high-performance photodetectors. Compared with vertical heterojunctions, in lateral heterojunction-based photodetectors, the reflection loss is reduced because the active layer is in direct contact with light resulting in higher performance and better stability. However, lateral perovskite-perovskite heterojunctions are difficult to achieve using solution methods because the first formed film is easily dissolved by the solvent of the second precursor. In this study, a two-step imprinting method is developed to fabricate lateral MAPbI(3)-MAPbBr(3) microwire heterojunctions and realize a high-performance photodetector with a responsivity and detectivity of 1207 A W-1 and 2.78 x 10(13) Jones, respectively. At 0 V bias, the device exhibits a responsivity of up to 233 A W-1, which is more than double the previously reported best results. The high-quality heterojunction endows the photodetectors with ultra-high polarization sensitivity (I-max/I-min = 8.2) and long-term stability, retaining 88.2% of its initial performance even after being exposed to air for 391 d.

Automated summary

Assembling perovskites into heterojunctions can achieve high-performance photodetectors, and lateral heterojunctions can improve performance and stability. In this study, a two-step imprinting method was developed to fabricate high-performance photodetectors with ultra-high polarization sensitivity and long-term stability.