Boosting the Performance of Flexible Perovskite Photodetectors Using Hierarchical Plasmonic Nanostructures

Plasmonic nanostructures can enhance the performance of photodetectors (PDs) owing to their amplification effect in light absorption, leading to overcoming the inherent properties of the photoactive layer. Herein, hierarchical plasmonic nanopatterns have been prepared and used for high‐performance flexible perovskite PDs. The developed hierarchical nanostructures, featuring nanoposts on cross‐nanograting patterns, exhibit a notably enhanced light trapping effect compared to hierarchical nanostructures based on a unidirectional simple nanograting structure. Moreover, hierarchical pattern‐based perovskite PDs show a photoresponsivity of 580 mA W −1 and a specific detectivity of 3.2 × 10 12 Jones, which are 420% and 990% higher than those of perovskite PDs without plasmonic nanostructures, respectively. Furthermore, a flexible 10 × 10 PD array has been developed, which enables the accurate mapping of light signals with exceptional operational and mechanical stabilities, under a bending radius as small as 8 mm and after undergoing more than 1000 bending cycles. Comprehensive analyses using finite‐difference time‐domain calculations and photoluminescence mapping reveal the effective light trapping effect of hierarchical plasmonic patterns in the perovskite layers. This work provides an efficient approach to achieve high‐performance perovskite optoelectronic devices.