Advancing Neutron Detection: Fabrication, Characterization, and Performance Evaluation of Self-Powered PIN BGaN/GaN Superlattice-Based Neutron Detectors

Solid state semiconductor based neutron detectors have the potential to be energy efficient and compact, making them suitable for applications where low power consumption and size constraints are important considerations. Herein, neutron detection devices based on PIN structures consisting of BGaN/GaN superlattice (SL) are demonstrated. These SL structures enable to incorporate significant boron (B) content and achieve good crystalline quality epilayers crucial for better neutron detection. Further, by leveraging the built-in electric field generated by the PIN structure, these devices can be operated without any applied bias, simplifying overall operation and enabling a more compact size system for detection. Their performance is evaluated by measuring real-time current response under neutron irradiation (I_N) and without it (I_D). The neutron induced current density (ΔJ = J_N − J_D) is determined, reaching an impressive value of 0.67 pA cm⁻² (two times J_D) under thermal neutron flux of 1.2 × 10⁴ n cm⁻² s⁻¹ without biasing, demonstrating their self-powered capability. They exhibit a linear response to varying thermal neutron flux levels. Additionally, the detectors successfully detect low thermal neutron fluxes down to 300 n cm⁻² s⁻¹, showcasing their potential for diverse applications, including in low neutron environments, screening nuclear warheads, and preventing illegal trafficking of radiological materials.