The new solar absorber, which is designed using simple and cost-effective fabrication technique, can harness more sunlight, which will then be converted into heat while enhancing efficiency.
The fabrication technique involves patterning tiny holes to the solar absorber. The holes with diameters less than 400 nanometers are cut into the absorber at regular intervals.
By penetrating the entire absorber, the tiny holes improve the range of absorbed solar energy.
The device, which requires very little material, has the potential to absorb close to 90% of all the light wavelengths that reach Earth’s surface while maintaining low emission levels.
Additionally, the absorber features only two layers which include a semiconductor film and a reflective metallic layer, with a total thickness of 170nm.
MIT postdoc Sang Hoon Nam and Masdar Institute postdoc Jin You Lu said in joint statement: "This idea can be applied to most conventional solar absorbers.
"With this unique patterning, the absorbers can be boosted to harvest more solar energy from the ultraviolet and visible regions of the electromagnetic spectrum."
MIT said that the work will contribute to a larger Masdar Institute-MIT research project, which intends to develop a solar-powered combined electrical power plant and cooling system.
MIT mechanical engineering professor Nicholas Fang said: "We are very excited that this MIT-Masdar Institute collaboration has led to new insights in the emerging field of plasmonics, which quantifies the interactions between the electromagnetic field and free electrons in a metal.
"By trapping sunlight with plasmonics, the solar absorber developed by our team can achieve higher efficiency levels. We look forward to testing the overall solar conversion efficiency of the coating materials in the next step of our research."
The researchers are seeking ways to optimize the system with alternative metals such as aluminum, copper, or silver, for the reflective metallic layer. This is expected to further reduce the costs of the solar absorber.
Image: Masdar Institute postdoc Jin You Lu. Photo: courtesy of Tahra Al Hammadi/Masdar Institute News.
