Ga₂O₃/GaN Heterointerface-Based Self-Driven Broad-Band Ultraviolet Photodetectors with High Responsivity

The broad-band ultraviolet (BBUV) photodetectors (PDs) responding to multiple ultraviolet (UV) wavelengths (230–400 nm) have received considerable attention in various fields, such as missile warnings, fire alarms, astronomical imaging, etc. Due to increased demand for BBUVPDs, there is a need for energy-efficient self-driven devices. This work used a simple thermal oxidation process to develop a β-Ga2O3/GaN heterointerface-based device that shows ultrahigh performance in self-driven, low bias, and spectrally broad responsive range. The fabricated device exhibits excellent stable performance in the self-driven mode of operation with an ultrahigh responsivity of 1.2 × 103 mA W–1 and a very high external quantum efficiency of 3.8 × 102% under 266 nm light illumination. Further, the performance of the fabricated device in the photoconductive mode (@5 V) displays an ultrahigh responsivity of 2.21 × 105 mA W–1, a very low noise equivalent power of 10–14 W Hz–1/2, and a very high external quantum efficiency of 104%. Furthermore, the device responds to the illumination wavelength of 355 nm, with a responsivity of 0.74 mA W–1 (2.2 × 104 mA W–1) at a 0 V (5 V) applied bias. The study will boost the prospects for creating next-generation optoelectronic devices to comprehend and utilize Ga2O3/GaN heterointerface devices.