Outperforming Transparent Ultraviolet Photodetectors Based on the AlGaN/GaN High Electron Mobility Transistor on SiC

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Current transparent ultraviolet (UV) photodetectors (PDs) exhibit suboptimal performance and utilize non-mainstream semiconductor materials, raising concerns about material quality and long-term durability.
• Aluminum Gallium Nitride/Gallium Nitride (AlGaN/GaN) high electron mobility transistor (HEMT) epi-structures on Silicon Carbide (SiC) present a promising alternative for advanced UV photodetection applications.

Purpose of the Study:

• To demonstrate the efficacy of AlGaN/GaN HEMT-based structures for developing high-performance transparent UV photodetectors.
• To establish new performance benchmarks for transparent UV photodetection using two- and three-terminal device configurations.

Main Methods:

• Fabrication and characterization of two- and three-terminal AlGaN/GaN HEMT-based transparent UV photodetectors.
• Evaluation of device performance metrics, including responsivity and dark current, to determine detectivity.

Main Results:

• Achieved detectivities of 2.17 × 10¹⁸ Jones for two-terminal and 3.18 × 10¹⁶ Jones for three-terminal AlGaN/GaN HEMT UV PDs.
• Demonstrated significantly higher performance compared to existing state-of-the-art transparent UV PDs.
• Highlighted the potential for industrial viability due to compatibility with mainstream GaN technology and a straightforward fabrication process.

Conclusions:

• AlGaN/GaN HEMT structures offer a pathway to industrially viable transparent UV photodetectors with unprecedented performance.
• The developed devices set new benchmarks in detectivity for transparent UV photodetection, addressing limitations of current technologies.
• The compatibility with GaN technology and simple fabrication suggest suitability for commercial production and long-term applications.