High-performance flexible and self-powered perovskite photodetector enabled by interfacial strain engineering

Abstract

Metal halide perovskites (MHPs) with excellent optoelectronic properties, a soft lattice and low-temperature solution processing have become promising candidates for flexible and self-powered photodetectors (FSPPDs) which exhibit tremendous potential for wearable and portable applications. Herein, we demonstrated a strategy to regulate the lattice strain by incorporating an extra hole transport layer (HTL) toward developing a high-performance perovskite-based FSPPD. The modified perovskite (MAPbI_3−xCl_x) film is compressively strained along the out-of-plane direction in comparison with the control film, according to XRD analysis. Consequently, the spin–orbit coupling (SOC) strength enhances in the perovskite film owing to the strain modulation, confirmed by the linearly/circularly polarized photoexcitation-modulated photocurrent and magneto-photocurrent measurements. The enhancement of SOC induces enlarged the Rashba effect, resulting in a prolonged carrier lifetime. Finally, the consequential MAPbI_3−xCl_x-based FSPPD manifests a remarkable improvement in the device performance with a maximum responsivity of 0.39 A W⁻¹ and detectivity of 2.31 × 10¹³ Jones at 660 nm.