High performance ultraviolet photodiode based on thin DPPT-TT donor–acceptor organic polymer

A high-performance ultraviolet photodetector based on a thin layer DPPT-TT organic material is experimentally demonstrated. The high absorption of DPPT-TT in the ultraviolet band is attributed to the foundation for a high-performance ultraviolet detector. The device's responsivity can be improved by adequately designing the hole-blocking layer HfO2 and the stepped structure at the bottom contact. Due to the self-filtering and optical trapping structure, the device achieves external quantum efficiency above 100%, even with a thin absorption layer (around 50 nm). The maximum spectral responsivity of the device is 383 A/W, and the corresponding maximum specific detection rate is about 2.79 × 1012 at a bias voltage of 0.5 V. Our results advocate that the thin organic ultraviolet photodetector promises excellent potential in low-cost ultraviolet-visible light detection and imaging applications.