Plasmon-Enhanced Performance in Self-Powered Solar-Blind CuCrO2/β-Ga2O3 Heterojunction Photodetectors with Al Nanoparticles

β-Ga
₂
O
₃
-based heterojunction photodetectors generally suffer from unsatisfactory low responsivity and low external quantum efficiency due to the carrier blocking from imperfect band alignment. Herein, we demonstrate for the first time the significantly improved performance of self-powered solar-blind CuCrO
₂
/β-Ga
₂
O
₃
heterojunction photodetectors by innovatively introducing Al nanoparticles prepared by a facile electron beam evaporation technology with the subsequent high-temperature annealing technique. Compared with the conventional CuCrO
₂
/β-Ga
₂
O
₃
photodetector, the responsivity, detectivity and external quantum efficiency of the CuCrO
₂
/β-Ga
₂
O
₃
photodetector with Al nanoparticles increase by 28.9, 39 and 28.9 times, respectively. In particular, our CuCrO
₂
/β-Ga
₂
O
₃
photodetectors show a low dark current of 3.67 pA, a high responsivity of 0.82 A/W, a high detectivity of 8.09 × 10
¹³
Jones, and a high external quantum efficiency of 402.8 %, which outperform most reported β-Ga2O3-based heterojunction photodetectors. Such brilliant performances can be attributed to the Al nanoparticles, which improve the efficiency of hole injection and accelerate the generation rate and separation speed of photogenerated carriers via the combined effect of the localized electric field and the localized surface plasmon resonance (LSPR). These results show that the CuCrO
₂
/β-Ga
₂
O
₃
photodetector with Al nanoparticles could achieve superior solar-blind sensitivity, thus providing a simple and feasible method to achieve high-performance ultraviolet photodetectors.