Radiation resistance and defect evolution in bulk β-Ga2O3: a molecular dynamics study

Benefitting from its wide bandgap and robust ionic bonding nature, beta-Ga2O3 is a critical material in extreme radiation environments. To investigate its radiation-resistant properties and microstructure evolution, molecular dynamics simulation is employed to systematically study the impact of different primary knock-on atom (PKA) energies (1.5, 3.0, 5.0 and 7.0 keV) and different temperatures (173, 300 and 800 K) on radiation-induced defects along [010] direction in bulk beta-Ga2O3 crystals. The result shows that the Frenkel pairs (FPs) yield increases linearly with PKA energy. The threshold displacement energy of Ga and O were calculated. Although the increase in temperature slightly improves the defect recombination rate, it also leads to more defects during the radiation cascade collisions. This occurs because the elevated temperature influences the movement of displaced atoms, creating more branch-like small sub-cascades. These branches cause greater local energy deposition, forming damage regions and resulting in more defects after irradiation. Additionally, when the energy exceeds 1.5 keV, sub-cascade clusters begin to split, indicating an energy-temperature coupling mechanism. This study is crucial for enhancing the displacement damage resistance of beta-Ga2O3-based devices and provides a foundation for subsequent testing and analytical results of beta-Ga2O3 and related materials.