Speaker
Description
Silicon carbide or SiC is widely used in various semiconductor devices, including PIN diodes, MOSFETs, and MEMS, due to its wide bandgap, large critical electric field, high thermal conductivity, high electron saturation velocity, chemical inertness, and radiation resistance. Among SiC polymorphs, 4H-SiC, with a bandgap of 3.26 eV, is the most studied and preferred for power electronics, bipolar devices, and quantum sensing due to its high isotropic charge carrier mobility. Recently, 4H-SiC has gained considerable attention as a promising material for radiation detection in extreme environments characterized by high temperatures and high radiation fluences. Despite previous challenges related to charge carrier trapping and recombination, as well as compensation effects from electrically active deep-level defects, advances in high-quality epitaxial 4H-SiC production have led to exceptional detection properties for alpha particles and neutrons. Additionally, promising results have been reported for the detection of low-energy gamma and X-rays. Notably, 4H-SiC detectors have demonstrated remarkable radiation hardness, maintaining functionality even after exposure to neutron fluences up to 1 × 10¹⁶ n_eq/cm². This resilience is attributed to the material's wide bandgap and high displacement energy, which mitigate radiation-induced defects. Furthermore, 4H-SiC devices exhibit low leakage currents and stable performance at elevated temperatures, making them suitable for applications in nuclear reactors and space missions.
This study presents the design of a versatile, cost-effective, and portable spectrometer for SiC radiation detectors intended for use in extreme environments. The spectrometer was initially characterized for alpha particle detection, leveraging the well-documented detection properties of SiC for such particles. Building on previous research demonstrating the effectiveness of 4H-SiC Schottky diodes with a thin ⁶LiF converter for neutron detection via the ⁶Li(n,α) reaction (with a Q-value of 4.78 MeV and a thermal cross-section of 940 barns), preliminary tests were also conducted for thermal neutron detection. These tests aim to evaluate the spectrometer's ability to distinguish neutron-induced reaction signals from gamma radiation background based on pulse height discrimination. The integration of 4H-SiC detectors into portable spectrometers offers a robust solution for radiation monitoring in harsh environments, combining durability, sensitivity, and operational stability.
