High detectivity photodetectors based on perovskite nanowires with suppressed surface defects

Abstract

Solution-processable, single-crystalline perovskite nanowires are ideal candidates for developing low-cost photodetectors, but their detectivities are limited due to a high level of unintentional defects. Through the surface-initiated solution-growth method, we fabricated high-quality, single-crystalline, defects-suppressed MAPbI 3 nanowires, which possess atomically smooth side surfaces with a surface roughness of 0.27 nm, corresponding to a carrier lifetime of 112.9 ns. By forming ohmic MAPbI 3 / Au contacts through the dry contact method, high-performance metal–semiconductor–metal photodetectors have been demonstrated with a record large linear dynamic range of 157 dB along with a record high detectivity of 1.2 × 10 14 Jones at an illumination power density of 5.5 nW / cm 2 . Such superior photodetector performance metrics are attributed to, first, the defects-suppressed property of the as-grown MAPbI 3 nanowires, which leads to a quite low noise current in the dark, and second, the ohmic contact between MAPbI 3 and Au interfaces, which gives rise to an improved responsivity compared with the Schottky contact counterpart. The realized high-performance MAPbI 3 nanowire photodetector advances the development of low-cost photodetectors and has potential applications in weak-signal photodetection.