Simulation of displacement damage in h-BN for neutron detection applications

• 1、School of Integrated Circuits, Dalian University of Technology, Dalian 116620

Abstract：Hexagonal boron nitride (h-BN) is a promising neutron detection material because of its ultra-wide bandgap, high resistivity, and feasibility of10B enrichment. However, neutron-induced displacement damage may degrade its long-term performance in harsh radiation environments. In this work, a Geant4-based Monte Carlo model of h-BN with 95% 10B enrichment was established to simulate neutron transport in the energy range of 1-20 MeV. Primary knock-on atom (PKA) spectra were obtained, and the non-ionizing energy loss (NIEL), number of displaced atoms (Nd), and displacements per atom (dpa) were evaluated using the modified Lindhard theory and the cascade collision model. The results show that low-energy neutrons mainly produce intrinsic B and N PKAs with energies concentrated in the low-energy region, whereas higher-energy neutrons generate more diverse light reaction products with significantly increased kinetic energies. NIEL is nearly uniformly distributed in thin targets, but decreases with penetration depth in thick targets and can approach zero in sufficiently thick materials. Both NIEL and dpa exhibit a nonmonotonic dependence on neutron energy, decreasing first and then increasing. In addition, nitrogen-related displacement damage remains higher than that of boron over the entire energy range. Elastic scattering dominates the displacement damage at low neutron energies, while inelastic scattering gradually becomes the major damage mechanism as neutron energy increases

Keywords： Semiconductor technology hexagonal boron nitride irradiation damage Geant4