Assessing high-energy x-ray and proton irradiation effects on electrical properties of P-GaN and N-GaN thin films

Abstract

The effects of ionizing and displacement irradiation of high-energy X-ray and 2 MeV proton on GaN thin films were investigated and compared in this study. The electrical properties of both P-GaN and N-GaN, separated from power devices, were gauged for fundamental analysis. It was found that the electrical properties of P-GaN were improved as a consequence of the disruption of the Mg-H bond induced by high-dose X-ray irradiation, as indicated by the Hall and circular transmission line model. Specifically, under a 100 Mrad(Si) X-ray dose, the specific contact resistance ρc of P-GaN decreased by 30%, and the hole carrier concentration increased significantly. Additionally, the atom displacement damage effect of a 2 MeV proton of 1×1013 p/cm2 led to a significant degradation of the electrical properties of P-GaN, while those of N-GaN remained unchanged. P-GaN was found to be more sensitive to irradiation than N-GaN thin film. The effectiveness of X-ray irradiation in enhancing the electrical properties of P-GaN thin films was demonstrated in this study.

Molecular dynamics simulations of dopant effects on lattice trapping of cracks in Ni matrix*

“…Experiments and simulations indicated that doping superalloys with Re, Ru, Co, and W improved their mechanical properties. [18][19][20][21][22][23][24][25][26][27] Our previous work reported the lattice trapping limit increased for the Ni or Ni 3 Al cracks when Re or W was added and that W incorporation yielded much stronger effects for the Ni 3 Al cracks. [4,13,15] Other reports indicated the effect of Co on the crack propagation along the γ/γ interface was minimal.…”