Ultra-sensitive ultraviolet organic photodetectors enabled by an expanded spectral window for health monitoring

• • The optimal ternary UV-OPD achieves a peak external quantum efficiency (EQE) of 78.29% at 340 nm, with EQE exceeding 53% across the 280–400 nm range, representing a significant improvement over conventional UV photodetectors. • • A high responsivity of 214.68 mA/W at 340 nm is attained, coupled with a rapid response time of 2.6/2.1 μs, marking the best reported combination of responsivity and speed in the UV region. • • Replacing conventional glass/ITO substrates with a quartz substrate and PH1000 electrode enhances UV transmittance, directly addressing the absorption losses that previously limited UV-OPD performance. • • The integration of the ternary blend PM6:Y6:PC71BM as the active layer is critical for achieving high UV absorption and efficient charge generation, enabling the device to operate effectively across the UV-A and UV-B spectral regions.