Multi-path charge transport in organic single crystals: a effective strategy to realizing ultra-sensitive organic ultraviolet photodetectors

Organic semiconductor materials enable simple fabrication and flexible device integration, making them attractive for next-generation UV organic photodetectors (UV-OPDs). However, the high-performance UV-OPDs remain scarce due to intrinsic material limitations: the high exciton binding energy ( E _B ) hinders free charge generation, while poor carrier mobility causes signal loss. Herein, we propose a multi-path charge transport strategy based on the synergistic regulation of molecules and crystals by introducing a large π-conjugated central nucleus to construct a D-π-A-π-D molecular structure that increase the π-conjugation and enhance planarity, which effectively promotes the π-overlap area between molecules, design and synthesize a novel perylene derivative (PDEDDP). The PDEDBDP single crystal (SC) exhibits multi-path charge transport between molecules, resulting in a smaller E _B and high mobility. Furthermore, the UV organic phototransistors (UV-OPTs) based on PDEDBDP SC achieve the highest photoresponsivity ( R ) up to 4.61 × 10 ⁷ A W ^-1 , which is one of the remarkable UV-OPT performance. This strategy provides a new idea for developing high-performance UV-OPDs.