Scientists at North Carolina State University are adding a new item to the growing menu of solar panel technology offerings.
In a new paper, the researchers say they have developed a means of creating a “nanoscale sandwich” that they believe will enable thinner solar panels, thus leading ti a possible “significant decrease” in panel manufacturing costs.
The thinner cells do not sacrifice any ability to capture solar power, they add.
“We were able to create solar cells using a ‘nanoscale sandwich’ design with an ultra-thin ‘active’ layer,” said Dr. Linyou Cao, an assistant professor of materials science and engineering at NC State. He is the co-author of the paper describing the research.
“For example, we created a solar cell with an active layer of amorphous silicon that is only 70 nanometers (nm) thick,” he explained. “This is a significant improvement, because typical thin-film solar cells currently on the market that also use amorphous silicon have active layers between 300 and 500 nm thick.”
The so-called active layer is where the solar cells absorb energy.
“The technique we’ve developed is very important because it can be generally applied to many other solar cell materials, such as cadmium telluride, copper indium gallium selenide, and organic materials,” Cao said.
Cao noted that the technique still deploys conventional manufacturing processes even while producing a much difference product.
“One key aspect of this technique is the design of the ‘nanoscale sandwich,’ with the active materials in the middle of two dielectric layers. The nanostructures act as very efficient optical antennas,” Cao saud, “focusing the solar energy into the active material. This focusing means we can use a thinner active layer without sacrificing performance. In the conventional thin-film design, using a thinner active layer would impair the solar cell’s efficiency.”
The end result is a pattern that creates a notched structure similar to that seen at the top of medieval castle walls.
The paper, “Dielectric Core-shell Optical Antennas for Strong Solar Absorption Enhancement,” was published in Nano Letters.
Lead author of the paper is Yiling Yu, a Ph.D. student. Other authors include Drs. Vivian Ferry and Paul Alivisatos of the University of California, Berkeley.
The U.S. Department of Energy provided part of the funding for the project.