Reversible oxygen vacancy generation on black zirconia ceramic surfaces via laser modification for solar energy harvesting

Abstract

Zirconia ceramic is considered as a promising solar absorber material due to its excellent physical and chemical properties. The creation of radiation-induced centers in zirconia ceramic improves its optical properties but usually needs high-temperature or high-pressure conditions. In this work, pulse laser modification and heat treatment are applied to modulate its optical properties in ambient air. Reversible oxygen vacancies are introduced by rapid cooling under short pulse duration laser irradiation. Laser processing parameters is investigated for the formation of broad absorption bandwidth and high intensity. At the optimized laser influence, laser-treated zirconia surface appears black with a reflectivity of less than 5 % in the visible range. Continuously adjustable reflectivity ranging from 5 % to 94 % can be achieved on oxygen-deficient zirconia due to the removal of defects via heat treatment at different temperatures. The introduction and removal of oxygen vacancies are supported by lattice contraction and stress release through XRD and XPS analyses. The enhanced solar absorption is demonstrated with a temperature difference of 7.6 °C under 1 sun illumination, which exhibits potential applications in solar energy harvesting and energy conversion.