Surface-passivated MAPbBr3 microwire with enhanced stability and suppressed ion migration

Abstract

One dimensional (1D) halide perovskites (HPs) have achieved tremendous progress in light emitting diodes, lasers, and photodetectors for their splendid optical properties, high mobility, and long diffusion length. However, unsatisfactory stability caused by inherent surface defects and notorious ion migration hinder their further development for commercial and practical applications. Herein, with the assistance of organic halide salts (phenyl-ethylammonium bromide (PEABr) and butylamine bromide (BABr)), we demonstrate a simple solution method for passivating the surface defects of the MAPbBr₃ microwire. Owing to the coordination bonding between amino groups and Pb²⁺, the PEA or BA molecules spontaneously assemble onto the surface of the as-fabricated microwire, leading to an obvious enhancement of the photoluminescence (PL) intensity and an extended PL lifetime. Meanwhile, negligible hysteresis was observed due to the suppressed ion migration. As a consequence, the constructed passivated microwire-based photodetector exhibits an increased responsivity of 35 mA W⁻¹, along with a −3 dB width of 740 Hz, a moderate LDR of 80 dB, and a weak noise current of 2.3 × 10⁻¹³ A × Hz^−0.5. Moreover, the device exhibits an enhanced stability for over 21 days under a humidity of 50%. This work provides an effective strategy to endow 1D perovskites with improved performance and stability for further applications in the future.