Enhanced optical absorption and mechanisms of A/B-sites co-doped LaCrO₃-based perovskite coating

Lanthanide ABO(3) perovskite materials are a kind of emerging optical materials in photothermal conversion devices due to the high temperature resistance and high absorptivity. Here, we reported a series of porous A/B-sites co-doped LaCrO3-based perovskite coatings, and investigated the effect of elemental doping on the optical properties and illuminated the enhancement mechanisms of optical absorption. The experiments and first-principle calculations demonstrate that the appropriate amount of Ca/Fe co-doping can decrease the bandgap and increase the number of free carriers, resulting in the enhanced absorptivity of ~ 95% and over 94% in the visible and near infrared regions and in the 0.3-14 mu m wavelength range, respectively. The La0.5Ca0.5Cr0.95Fe0.05O3 coating has optimal photothermal conversion performance compared with the un-doped and Ca-doped LaCrO3 coatings under solar and infrared irradiations. This study provides a simple and convenient process to prepare high-performance photothermal coatings, which is of great application potential in energy conversion in wide-spectrum range.