Fabrication of black metal surface for high solar energy absorption by femtosecond laser hybrid technology.

Metals are crucial for solar energy applications, but their highly reflective surfaces limit solar energy absorption. The difficulty in manufacturing an ideal light-absorbing structure limits the incorporation of anti-reflective characteristics in metals. In this study, a femtosecond laser method was introduced to form micro-nano structures in metals, enhancing absorption by the application of silver nanoparticles and resulting in solar absorption rates of 97.2%, 98.3%, and 98.9% for aluminum, titanium, and steel, respectively. The solar reflectance was reduced by 82.3%, 62.6%, and 79.2%, respectively, compared to bare metal. Photothermal conversion and deicing tests verified a more efficient photothermal conversion ability in the composite micro-nanostructure surface. Compared to bare metal, the structure has more than twice the solar absorption efficiency and improves the deicing efficiency by 132%. The resultant material exhibits high photothermal conversion and deicing efficiencies, enhancing its potential for solar energy applications, particularly in photothermal, photovoltaic, and thermal solar technologies.