Influence of DNA Solution on Dark and Deep-UV Response of Ga 2 O 3 /p-Si Schottky Diodes

This study investigates the influence of DNA solution on the photoelectric characteristic of amorphous Ga₂O₃/p-Si Schottky diodes. Experiment results reveal that the presence of a DNA droplet on the Ga₂O₃ surface significantly influences the device behavior. Upon applying a DNA droplet onto the devices, the dark current increased from 3.22×10⁻⁶ A to 8.31×10⁻⁶ A, owing to the interfacial charge redistribution induced by negatively charged phosphate backbone and its associated counter ions. Conversely, under 254 nm deep–ultraviolet (DUV) illumination, the photocurrent decreases from 1.04 × 10⁻⁴ A to 3.06 × 10⁻⁵ A due to the strong deep–ultraviolet absorption of DNA nucleobases. To analyze junction parameters, the Ocaya–Yakuphanoğlu (O–Y) method was employed, overcoming the non-physical fluctuations of conventional models. The O–Y method extraction confirmed that the presence of DNA droplet reduces the barrier height, explaining the increased leakage current. These findings establish a foundation for future Ga₂O₃-based deep–ultraviolet biosensing platforms.