Effect of 1-MeV Equivalent Neutron Irradiation on the Electrical Characteristic of NiO_x/β-Ga₂O₃ p-n Diode

In this article, the impact of 1-MeV equivalent neutron irradiation on the electronic properties of NiO_x/beta-phase gallium oxide (β-Ga₂ O₃) p-n diode has been investigated. After neutron irradiation with a fluence of 1 x 10¹⁴ n/cm², the forward current density (J_F) decreased by 23%, the leakage current density (J) was reduced by 45.6%, and the breakdown voltage (V_br) increased by approximately 216 V, as measured by current − voltage (I–V) analysis. The capacitance− voltage (C– V measurement shows that the carrier concentration in the lightly doped n-type β-Ga₂O₃ drift layer decreased from 1.96 x 10¹⁶ to 1.74 x 10¹⁶ cm^-3 after neutron irradiation. The effect of neutron irradiation on the trap states was studied using frequency-dependent conductivity techniques. It is revealed that the density of trap states at NiO_x/ β-Ga₂O₃ increases significantly from 1.12 to 1.4 9x 10¹² cm^-2 .eV^-1 to 3.76- 5.80 x 10¹² cm^-2.eV^-1, accompanied by a slight decrease in trap activation energy from 0.091 to 0.187 eV to 0.086-0.185 eV after neutron irradiation. Additionally, deep-level transient spectroscopy (DLTS) measurements indicate that the trap at an energy level of E_C–E_T = 0.75 eV, induced by neutron irradiation, is likely the primary cause of the degradation in NiO_x/β-Ga₂O₃ p-n diode properties. These findings can offer significant theoretical insights for the design of future anti-radiation hardening.