High-Performance Solar-Blind Ultraviolet Photodetectors Based on a Ni/β-Ga₂O₃ Vertical Schottky Barrier Diode

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Gallium oxide (Ga₂O₃) is a promising material for solar-blind ultraviolet (SBUV) photodetectors due to its wide bandgap and fast photoresponse.
• Performance limitations in Ga₂O₃ Schottky photodiodes are often attributed to the Schottky contact quality, hindering optimal detection capabilities.

Purpose of the Study:

• To develop a high-performance Ni/β-Ga₂O₃ vertical Schottky barrier diode (SBD) with an ultrathin anode.
• To improve the Schottky junction quality through simple surface treatment for enhanced photodetector performance.

Main Methods:

• Fabrication of a Ni/β-Ga₂O₃ vertical Schottky barrier diode (SBD) utilizing an ultrathin anode electrode.
• Implementation of a simple surface treatment to enhance the Schottky junction quality.
• Characterization of device performance, including dark current, photo-to-dark current ratio (PDCR), specific detectivity (D*), response time, and high-temperature operation.

Main Results:

• Achieved a record-low dark current of less than 12 fA.
• Demonstrated an ultrahigh photo-to-dark current ratio (PDCR) of 4.92 × 10⁷ and specific detectivity (D*) of 2.76 × 10¹⁵ Jones.
• Reduced response time to the millisecond order and confirmed stable operation at 150 °C.

Conclusions:

• The developed Ni/β-Ga₂O₃ SBD with an ultrathin anode and improved Schottky junction offers superior performance for SBUV detection.
• The simple surface treatment approach facilitates mass production of high-performance Ga₂O₃ photodetectors.
• These findings indicate significant potential for advanced UV imaging applications.