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

## TL;DR

A flexible photodetector combining perovskite and organic layers achieves high efficiency and fast response for optical communication and imaging.

## Contribution

Integration of perovskite and organic bulk-heterojunction for broadband, high-speed photodetection with self-powered operation.

## Key findings

- Device achieves 84% visible and 63% near-infrared external quantum efficiency.
- Photodetector exhibits a self-powered responsivity of 0.3 A W−1 and 29 µs response time.
- Enables 25-pixel flexible array with low bit error rate for high-speed optical communication.

## Abstract

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 (Csn.15FAn.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 (JD) to 6.9 × 10−11 A cm−2 and noise current (in) 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.

A flexible broadband photodetector is realized by integrating a perovskite with an organic bulk‐heterojunction. It achieves high external quantum efficiency (EQE) (>80% visible, >60% near‐infrared (NIR)), ultralow dark current, and fast response, enabling self‐powered, high‐detectivity operation. The device facilitates robust NIR imaging, health monitoring, and high‐speed optical communication on a flexible platform.