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

Abstract

Optical 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.

Hierarchical structure regulation for sequential steps in solar vapor generation

“…4,80 The excited electrons release heat through electron-phonon coupling relaxation, resulting in an increase in temperature (Figure 3F). 81 Consequently, abundant conjugated bonds can generate more π electrons, the solar thermal conversion performance would be optimized.…”

Exploring the Effects of Laser Surface Modification on AISI 301LN Steel: A Micro-Mechanical Study

“…The amount of hardness increase that occurred on the near surface level is directly related to the scanning speed and laser energy, as shown in Figure 8a. Reducing the speed of the laser induces a greater local concentration of thermal energy, and since the percentage of overlapping of each laser spot keeps constant, it can induce an overlapping process in terms of energy concentration and heat at the same point, in concordance with [29][30][31]. Due to all these above-mentioned factors being presented, the thermal reversion treatment takes place at the mentioned point.…”