β-Ga2O3 photodetectors with high-performance enhanced by field control via p-type NiO interlayer

Gallium oxide (Ga 2 O 3 ) film exhibiting the solar-blind absorption cutoff characteristic holds considerable potential for application in UV photodetectors . The material defects in the device will introduce the recombination region for the photodetector, especially at the interface of the Ga₂O₃ heterojunction . The photogenerated carriers , generated within the Ga 2 O 3 film, will inevitably be influenced by these high recombination centers during their transportation. Avoiding or minimizing this region can improve the performance of the photodetector. The p-n junction, with its depletion region , generates an electric field that drives the carriers away from the recombination region. However, due to the Ga 2 O 3 p-type doping difficulty, our work focuses on the growth of single-crystal NiO/β-Ga₂O₃ films by Mist-CVD and the fabrication of field-controlled photodetectors. The hole concentration in the NiO film is adjusted by doping with different concentrations of Li⁺. Compared with a photodetector without the NiO interlayer, the performance of the photodetector with the structure of NiO (1 % Li⁺-doped)/β-Ga₂O₃ exhibits a significant improvement, which achieved the maximum responsivity of 1002.5 A/W, and a high peak detectivity of 3.31 × 10 15 Jones.