Molecular Doping Induced High‐Performance Filterless Red‐Light Organic/Perovskite Photodetectors for Quantitative Analysis of Medical Photosensitizer Materials

ABSTRACT

Red‐light narrowband photodetectors play indispensable roles in the photomedical industry, particularly in applications such as fluorescence imaging, photodynamic therapy, and non‐invasive optical diagnostics. Herein, we introduce a novel device architecture (OP‐PDs) that achieves short‐wavelength light filtering through an organic layer and target light response via a perovskite material, enabling selective red‐light detection in the range of 600–730 nm. Doping the organic layer with Me‐4PACz leads to substantial performance enhancements in OP‐PDs, and the optimized device OP‐PD‐7 demonstrates exceptional sensitivity to faint red light. Under unbiased conditions, the device achieves an external quantum efficiency of 72.96% and a responsivity of 0.38 A/W at the peak red wavelength of 650 nm, demonstrating competitive performance among red‐light narrowband photodetectors, particularly in terms of bias‐free operation and spectral selectivity. By utilizing its excellent ability to detect weak red light signals, OP‐PD‐7 was used to characterize the fluorescence properties of a medical photosensitive material protoporphyrin IX (PpIX). The result shows practical potential applications in photomedical applications by addressing critical challenges in weak‐signal detection and spectral selectivity.