Enhancing laser-induced damage threshold of cubic HfO₂ thin film via Y₂O₃ doping

Hafnium oxide (HfO₂) is a widely used material in high-energy laser systems. However, the laser-induced damage threshold (LIDT) is limited by its intrinsic thermophysical properties and volume changes during phase transitions. In this study, we enhance the LIDT from 5.51 J/cm² to 10.11 J/cm² by Y₂O₃ doping via magnetron co-sputtering. The effects of Y₂O₃ doping on the properties of HfO₂ films have been systematically investigated, including crystalline structure, surface morphology, optical and thermophysical properties. The increase in LIDT is attributed to the reduced temperature gradient resulting from optimized specific heat capacity, as well as the suppression of phase transformation stresses through cubic phase stabilization. Notably, COMSOL Multiphysics simulation results indicate that surface roughening of the film due to intensified crystallization leads to the formation of heat accumulation micro-zones, consequently aggravating ablation damage. These findings provide a novel processing route for fabricating HfO₂ films with high LIDT, highlighting the potential applications of cubic Y₂O₃-doped HfO₂ in high-energy laser systems.