Organic Bulk‐Heterojunction‐Integrated Flexible Perovskite Photodetection Arrays for High‐Speed Broadband Optical Communication

The demand for self-powered, broadband photodetectors is rising in fields like artificial intelligence, health monitoring, and optical communications. However, conventional perovskite photodetectors face limited visible absorption and poor ambient stability. Here, we report a high-performance integrated photodetector combining a perovskite (Cs_n.15FA_n.85PbI₃) absorber with an organic bulk-heterojunction (BHJ) structure for broadband photon harvesting up to 1000 nm. The device achieves a peak external quantum efficiency (EQE) of 84% in the visible range (400-700 nm) and 63% in the near-infrared (NIR, 700-1000 nm). Benefiting from optimized energy band alignment, the photodetector exhibits a self-powered responsivity of 0.3 A W^-1 and a fast response time of 29 µs, with a linear dynamic range (LDR) of 122 dB under 900 nm NIR illumination. The BHJ organic layer suppresses the dark current (J_D) to 6.9 × 10^-11 A cm^-2 and noise current (i_n) to 10-14 A Hz^-1/2, yielding a specific detectivity (D*) of 10¹² Jones. The polymeric BHJ also enhances flexibility, enabling a reliable 25-pixel array for uniform NIR imaging. In optical communication, the device achieves a low bit error rate with data rates of 90 kbps (λ = 665 nm) and 140 kbps (λ = 904 nm). This work establishes the perovskite/BHJ detector as a promising platform for flexible, high-speed optoelectronics.