High-Performance Perovskite Photodetector through Plasmonic Enhancement of Carrier Dynamics

We present a high-performance metal-semiconductor-metal photodetector based on a triple-cation metal halide perovskite (TCMHP) integrated with interdigitated electrodes and a plasmonic superstrate engineered to prolong the lifetime of photogenerated carriers, which leads to more efficient charge carrier collection, thereby resulting in enhanced responsivity and faster switching. Our photodetector demonstrates a four-orders-of-magnitude enhancement in photocurrent and responsivity compared to control devices, supported experimentally by time-resolved photoluminescence measurements that show a 3-fold increase in carrier lifetime within the TCMHP film. This enhancement in the carrier lifetime is attributed to suppressed carrier recombination enabled by the plasmonic superstrate, in addition to inherent slow carrier trapping/detrapping dynamics within the in-plane dominant TCMHP film. Our detector offers a high responsivity of ∼1880 A W^-1 and a specific detectivity of ∼2.2 × 10¹² Jones, as well as an on/off ratio of ∼8.11 × 10³, highlighting the effectiveness of combined plasmonic and material engineering strategies. It also exhibits rise and fall times of 600 and 650 μs, respectively, and attains outstanding switching behavior under periodic light on/off cycles along with stable and reproducible photocurrent over a period of days in open air.