Localized Surface Plasmons Contribute to Highly‐Efficient Carrier Transport and Injection in Interface‐Engineered Solar‐Blind UV Photodetector

Wide bandgap semiconductor Ga 2 O 3 has been a hot photosensitive material for constructing solar‐blind UV photodetectors. Ga 2 O 3 ‐based heterojunction photodetector could operate without external power source, since the development of built‐in electric field. Its photodetection performances can be improved by interface engineering. In this work, a PEDOT:PSS/Ga 2 O 3 heterojunction photodetector is introduced and discussed, in which, the Ag nanoparticles are used to decorate the interface, and the performances are enhanced by localized surface plasmon resonance. In detail, the optimized detector achieved a responsivity of 59 mA/W, an external quantum efficiency of 29%, and a specific detectivity of 3.3 × 10 12 Jones at zero bias. The rise and decay times are 87 and 288 ms, respectively. Moreover, the device demonstrates potential in optical communication systems and multifunctional optical logic gates, highlighting a valuable insight and a novel strategy for UV solid‐state optoelectronics.