Self-powered radiation detector based on an AlScN/SiC heterojunction structure.

Area of Science:

• Materials Science
• Semiconductor Physics
• Nuclear Instrumentation

Background:

• Conventional Silicon Carbide (SiC) alpha particle detectors require high applied bias (tens to hundreds of volts).
• Existing detectors face limitations in power consumption and operational complexity due to external bias requirements.

Purpose of the Study:

• To develop and demonstrate a self-powered alpha particle detector based on an AlScN/SiC heterojunction.
• To investigate the underlying mechanism enabling self-powered operation and enhanced detection performance.

Main Methods:

• Fabrication of an AlScN/SiC heterojunction structure with optimized AlScN film thickness.
• Characterization of detector performance, including dark current and energy resolution, under various alpha particle sources without applied bias.
• Analysis of the type II heterojunction band alignment and charge carrier dynamics.

Main Results:

• Achieved a low dark current of 1.3 nA/cm² at -40 V.
• Observed distinct alpha particle peaks for 239Pu, 241Am, and 244Cm with high energy resolutions (3.7%, 4.2%, 3.3%).
• Demonstrated self-powered detection capability attributed to hole accumulation and electron multiplication at the AlScN/SiC interface.

Conclusions:

• The AlScN/SiC heterojunction enables efficient self-powered alpha particle detection.
• Optimized AlScN film thickness and heterojunction properties are crucial for performance.
• This approach offers a promising strategy for developing advanced, bias-free radiation detectors.