Ultrasensitive, flexible perovskite nanowire photodetectors with long‐term stability exceeding 5000 h

Abstract Photodetectors (PDs) based on perovskite nanowires are among the most promising next‐generation photodetection technologies; however, their poor long‐term stability is the biggest challenge limiting their commercial application. Herein, an ionic liquid, 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BMIMBF 4 ), is incorporated as an additive into methylammonium lead triiodide (MAPbI 3 ) nanowires; this not only effectively passivates defects to inhibit perovskite degradation but also leads to the formation of nanochannels, enabling fast charge transfer. As a result, the long‐term stability and performance of MAPbI 3 nanowires are considerably improved. The detectivity, linear detection range, and noise equivalent power of the MAPbI 3 nanowire PD reach 2.06 × 10 13 Jones, 160 dB, and 1.38 × 10 −15 W Hz −1/2 , respectively, comparable to the highest performance of perovskite nanowire PDs reported to date. Moreover, the unencapsulated PD can maintain 100% of its initial performance after being exposed to an open‐air environment for more than 5000 h, establishing it as the most stable perovskite nanowire PD reported to date. Notably, the PD exhibits improved diffuse reflection imaging ability when compared with commercial silicon photodiode S2386. This study provides a new strategy for constructing sensitive, stable, and flexible perovskite PDs and will accelerate their commercial application in the future. image