Comparative Study of Radiation Hardness in Semiconductor Materials (Si, SiC, GaN, Diamond) for Americium-241 Waste-Based Nuclear Batteries

Abstract

Using Americium‑241 (Am‑241) radioactive waste from spent smoke detectors as an alpha‑voltaic energy source provides a long‑term power solution for sensors in extreme environments. However, high‑energy alpha particles (5.48 MeV) are inherently destructive to semiconductor crystal structures. This study aims to identify the optimal Wide Bandgap (WBG) material by analyzing energy‑loss mechanisms (stopping power), lattice damage, and device geometry design parameters. SRIM 2013 simulations were performed on Si, SiC, GaN, and diamond targets. The analysis includes ion distribution range, electronic and nuclear stopping profiles, the calculation of a Radiation Tolerance Index, and the determination of minimum active thickness (T_min) based on projected‑range statistics. The results show that diamond exhibits the highest tolerance index of 670, enabling the thinnest device design (~15 µm). In contrast, silicon requires nearly twice the active thickness (~28 µm) and suffers the most severe structural damage. Silicon carbide (SiC) is recommended as a cost‑effective alternative with a Radiation Tolerance Index of 593. While diamond is the superior material for space‑constrained applications, SiC offers the best balance between radiation resistance and cost for terrestrial applications.