Laser-Induced Defects in Metal Oxides: A Perspective.

Defects govern the electrical, mechanical, optical, and diffusion-related properties of metal oxides, making defect engineering a powerful strategy for tailoring material performance. Conventional approaches, including thermal annealing, chemical doping, ion implantation, and atmospherecontrolled processing, are largely constrained by equilibrium processing and provide limited control over defect type, spatial distribution, depth, and evolution. Pulsed laser processing offers a versatile platform for localized, non-equilibrium defect engineering in metal oxide nanomaterials. Hierarchical defect structures, including vacancies, dislocations, grain boundaries, and interfaces, can be generated and manipulated over multiple length scales to enhance charge transport, optoelectronic performance, and plasticity. These defects can also accelerate diffusion for low-temperature sintering and nanojoining. Beyond summarizing recent advances, this Perspective highlights emerging directions in defect-dynamics design, including the controlled generation, migration, interaction, and stabilization of defects through adaptive laser processing, as well as control over defect depth, orientation, and time-dependent evolution. Finally, predictive relationships among laser parameters, defect dynamics, and functional properties are expected to emerge through the integration of in situ characterization, multiscale modeling, and artificial intelligence, enabling application-specific design of advanced metal oxides.