The active layer (blue line) is sandwiched between layers of dielectric material.
Researchers from North Carolina State University have found a way to create much slimmer thin-film solar cells without sacrificing the cells’ ability to absorb solar energy. Making the cells thinner should significantly decrease manufacturing costs for the technology (see paper in Nano Letters: “Dielectric Core–Shell Optical Antennas for Strong Solar Absorption Enhancement”).
“We were able to create solar cells using a ‘nanoscale sandwich’ design with an ultra-thin ‘active’ layer,” says Dr. Linyou Cao, an assistant professor of materials science and engineering at NC State and co-author of a 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. 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 “active” layer in thin-film solar cells is the layer of material that actually absorbs solar energy for conversion into electricity or chemical fuel.