Have you succeeded in developing a perfect solar energy absorber?

It has succeeded in producing perfect solar energy absorption by laser processing the metal surface. Using this, it is possible to create an ideal solar power generation system.

A research team at Rochester, inspired by the ability of spiders and ants to float, developed a floating metal. The metal floating in the water is to give strong hydrophobicity to the metal surface by using a femtosecond laser with increased laser intensity that oscillates with a short pulse width.

The research team succeeded in developing a rescue element for the creation of an efficient solar power generation system with a processing technology that utilizes femtosecond lasers, such as those used for processing floating metal. The Institute of Optics at the University of Rochester, which led the research, has been conducting research for the past few years to add properties such as hydrophilicity and hydrophobicity to metals using femtosecond lasers.

The result is a metal floating in water with added superhydrophobicity. Dropping water drops on metal that floats on water reflects the water droplets off the surface. The research team is challenging to significantly increase the solar absorption rate by blackening the metal surface with a femtosecond laser. Of course, just by darkening the metal surface, wavelengths other than the solar spectrum are emitted as heat. To solve this problem, the research team has developed a selective absorber that absorbs the solar spectrum and loses little heat of other wavelengths.

In general, most of the light is reflected off the surface of a piece of metal, but if the metal surface is properly processed with a femtosecond laser, the light is not reflected off the metal surface and the necessary energy can be absorbed completely. Incorporating the selective absorption developed by the research team into a thermoelectric power generation device increases power generation efficiency by 130% compared to normal. In addition, it is said that selective absorption can absorb a wide spectrum of 15%, even when compared to a metal whose surface is only processed in black.

Selective absorption optimizes solar and thermal energy collection by minimizing heat loss while trapping certain wavelengths. The researchers say that for the first time, they have succeeded in producing the selective absorption of the perfect metal for the first time.

The research team also succeeded in selectively absorbing metals such as aluminum, copper, steel, and tungsten by processing them with a femtosecond laser. It is said that tungsten, which is commonly used for heat absorption, has the highest solar absorption efficiency. Related information can be found here .