Deep-Ultraviolet Photodetection Using Single-Crystalline β-Ga₂O₃/NiO Heterojunctions

Area of Science:

• Materials Science
• Condensed Matter Physics
• Optoelectronics

Background:

• Recent interest in β-Ga₂O₃/NiO heterojunction diodes.
• Lack of literature on epitaxial growth and device fabrication using electron microscopy.

Purpose of the Study:

• Investigate epitaxial growth of β-Ga₂O₃/NiO thin films.
• Fabricate and characterize solar-blind ultraviolet photodetectors.
• Analyze heterostructure properties and band alignment.

Main Methods:

• Pulsed laser deposition for thin-film growth.
• X-ray crystallography, ion beam analysis, and electron microscopy for characterization.
• High-resolution X-ray photoelectron spectroscopy for band offset determination.

Main Results:

• Achieved single-crystalline (2̅01) β-Ga₂O₃ and (111) NiO films.
• Confirmed sharp interfaces and high quality in the NiO/β-Ga₂O₃/sapphire stack.
• Demonstrated solar-blind photodetectors with peak responsivity at 260 nm.
• Determined type-I band alignment with specific valence and conduction band offsets.

Conclusions:

• Successfully fabricated high-quality β-Ga₂O₃/NiO heterostructures.
• Developed efficient solar-blind ultraviolet photodetectors.
• Provided crucial insights into heterostructure properties and band alignment for device optimization.