Synergistic enhancement of optical properties in Ca/Ni co-doped LaFeO3 perovskite coatings enabling high-temperature photothermal conversion

Abstract

Perovskite-type oxides (ABO3) are widely acknowledged as novel light-absorbing materials owing to their adaptable composition, distinctive oxidation states, and customizable physicochemical properties. In this study, we reported a series of A-site or A/B-sites doped LaFeO3-based ceramic coatings for photothermal conversion. An exhaustive investigation was undertaken to explore the effects of doping element on the microstructure, microchemistry, and optical properties of the ceramic coating. Among all the samples, the La0.5Ca0.5Fe0.95Ni0.05O3 coating exhibits the highest absorptivity in the solar spectrum (300–2500 nm) and in the wavelength range of 0.3–14 μm, reaching 92.2 % and 88.1 %, respectively. Furthermore, it demonstrated the superior photothermal conversion performance under solar and infrared radiation. Complementary first-principles calculations provide fundamental principles for comprehending the light absorption enhancement mechanisms in LaFeO3-based materials, revealing the complex interplays between crystal structure, band structure, and light absorption. The experimental findings, along with the results of first-principles calculations, demonstrate that the doping of Ca or Ca and Ni can effectively reduce the bandgaps and induce lattice distortions, thereby enhancing the light absorption in the visible and infrared wavebands. This work presents a facile method to prepare LaFeO3-based coatings with different morphologies, providing a novel option for high-temperature photothermal conversion applications.