Mass‐Producible Self‐Powered Solar‐Blind Ultraviolet Photodetector Based on Graphene/ β ‐Ga 2 O 3 Heterojunction Processed by Wet Transfer

Abstract Graphene electrodes draw considerable attention in solar‐blind ultraviolet (SBUV) detection owing to their unique features including high ultraviolet (UV) transparency and superior intrinsic carrier mobilities. However, their adoption comes with challenges, as the most commonly used preparation technique, i.e., the dry transfer process, is challenging to achieve mass production. In this work, graphene/ β ‐Ga 2 O 3 heterojunction photodetectors processed by wet transfer are reported. Benefiting from the UV‐transparent electrode and heterojunction, both the responsivity and response speed are improved. The characteristic of the graphene/ β ‐Ga 2 O 3 interface is analyzed by the current–voltage ( I – V ) and capacitance–voltage ( C – V ) curves, featuring a high‐quality junction. Operated at zero bias, the photodetector exhibits a low dark current of less than 1 pA and a high response speed of less than 1 ms. An excellent UV‐C/visible rejection ratio is also achieved. Importantly, the photodetector performs excellent reproducibility and performance stability. This results provide a new perspective for the mass production of graphene/Ga 2 O 3 integrated devices, enabling high‐performance Ga 2 O 3 photodetector arrays.