High-Performance Ga₂O₃ Solar-Blind Photodetector Based on Thermal Oxidized Ga Buffer-Layer

Area of Science:

• Materials Science
• Semiconductor Physics
• Optoelectronics

Background:

• High-performance solar-blind photodetectors are crucial for ultraviolet applications.
• The quality of Gallium Oxide (Ga₂O₃) films directly impacts photodetector performance.
• Defects and lattice mismatches in Ga₂O₃ films limit device efficiency.

Purpose of the Study:

• To enhance the quality of Ga₂O₃ films for improved photodetector performance.
• To introduce a naturally graded buffer layer for better interface stability.
• To investigate the effectiveness of this buffer layer in reducing defects and accommodating lattice mismatches.

Main Methods:

• Fabrication of Ga₂O₃ films with a naturally graded buffer layer formed by oxidizing a metallic Ga film.
• Comprehensive structural and compositional analysis using UV-vis spectroscopy, Atomic Force Microscopy (AFM), Photoluminescence Spectroscopy (PL), Transmission Electron Microscopy (TEM), and X-ray Photoelectron Spectroscopy (XPS).
• Fabrication and characterization of solar-blind photodetectors using the enhanced Ga₂O₃ films.

Main Results:

• The naturally graded buffer layer significantly improved interface stability.
• Structural and compositional analyses confirmed reduced defects and accommodated lattice mismatches.
• Photodetectors exhibited a responsivity of 99.8 mA/W and a solar-blind UV/UV ratio of 1.17 × 10³.
• Performance showed significant improvement compared to photodetectors made from directly deposited Ga₂O₃ films.

Conclusions:

• Naturally graded buffer layers are an effective strategy for enhancing Ga₂O₃ film quality.
• This approach offers a promising pathway for advancing the performance of Ga₂O₃-based solar-blind UV detectors.
• The developed method contributes to the field of high-performance ultraviolet optoelectronic devices.