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

Abstract

Conventional SiC alpha particle radiation detectors typically operate under an applied bias of tens to hundreds of volts. This study introduces a self-powered alpha particle detector using an AlScN/SiC heterojunction structure. By optimizing the thickness of the AlScN film, the detector achieves a low dark current (1.3 nA/cm² at -40 V). Three distinct alpha particle peaks are observed with energy resolutions of 3.7%, 4.2%, and 3.3% for ²³⁹Pu, ²⁴¹Am, and ²⁴⁴Cm, respectively, without external bias. The self-powered capability results from the type II heterojunction between AlScN and SiC, where the hole potential well at the AlScN/SiC interface accumulates holes and enables electron multiplication. The collection of additional current generated by supplementary electrons during transport enhances detection performance without applied bias. This study elucidates the underlying mechanism and proposes an effective strategy to advance SiC-based radiation detection.