Dopant-Mediated Stokes Shifting in Perovskite Quantum Dots for Enhanced UV-Stable Organic Photodetection

Abstract

Ultraviolet (UV) photodetection is critical for applications spanning environmental monitoring to optical communication; however, the high photon energy of UV light introduces inherent trade-offs between sensitivity and operational stability. In particular, organic photodetectors (OPDs) exhibit severe instability under high-energy UV (UVB–UVC) irradiation, where photo-oxidation and trap-state formation cause rapid performance degradation. Here, a hybrid luminescent concentrator–organic photodetector (LC–OPD) platform incorporating Stokes-shift-engineered Mn-doped CsPbCl3 perovskite quantum dots is presented for stable UV and deep-UV photodetection. Dopant-induced deep intragap emission generates a large Stokes shift (∼200 nm), spectrally decoupling UV absorption from visible emission and enabling reabsorption-free down-conversion. This photon-management strategy converts high-energy UV photons into OPD-compatible visible light, effectively protecting the organic layers from direct UV exposure. The LC–OPD achieves linear dynamic ranges of 96.3 dB at 375 nm and 72.1 dB at 285 nm, with specific detectivities of 5.45 × 1011 and 1.13 × 1011 cm Hz0.5 W–1, respectively, while retaining 91% of its performance under continuous UV illumination. The platform further enables stable UV optical communication using ASCII-encoded binary signals. This work demonstrates a scalable photon-management approach that integrates spectral conversion, high sensitivity, and long-term UV stability for next-generation organic UV photodetection.