High‐Performance and Stable Dual‐Nanograting‐Perovskite‐Based Near‐Infrared Photodetector

Potential applications of perovskite materials in near-infrared (NIR) photodetectors are hindered by their instability and low absorption. In this study, dual nanogratings and upconversion nanoparticles (NaYF₄:20%Yb, 2%Er) are introduced to enhance the stability of MAPbBr₃ and extend its spectral response to the NIR range. A photodetector with responsivity of 2.9 A·W^-1 and detectivity of 1.34×10¹¹ Jones at 980 nm is developed using this approach. The device maintained 78.6% performance after 4 months of air exposure and 72.4% performance after 3000 bending cycles, demonstrating significant improvements in stability and flexibility.