Femtosecond laser‐produced optical absorbers for solar‐thermal energy harvesting

Abstract

AbstractOptical absorbers are a key component in all solar‐thermal energy technologies. Cermet‐based solar absorbers are commonly used in solar‐thermal applications. However, due to their multilayered structures, these absorbers have limited thermal conductivity and mechanical stability at the interfaces. Femtosecond laser processing is a single‐step, environmentally friendly, and monolithic approach that can directly transform a metal surface to a solar absorber through surface patterning without adding additional weight, hazard, or complexity. In this review, we will focus on femtosecond‐laser induced broadband and selective solar absorbers and their utilizations in solar thermoelectric generators and solar‐thermal water purification. We will discuss the laser surface patterning and the procedure to control the size, distribution, and composition of the surface structures that are responsible for optical absorbance/emittance. Several multifunctional solar absorber surfaces produced by femtosecond‐laser processing and their possible energy applications are also discussed.image