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.