Solar Harvesting Windows Possible With Advances in Semiconductors

New semiconductor technology is advancing the development of house windows that could double as solar panels, according to scientists from Los Alamos National Lab and Italy. Their research into so-called “quantum dots” — ultra-small bits of semiconductors that transmit energy extremely efficiently and can be tuned toward specific colors — shows that quantum dots can be used in transparent materials to harvest sunlight with efficiencies comparable to standard solar panels.

When highly transparent materials are embedded with quantum dots, they are known as luminescent solar concentrators (LSCs); the structures can absorb sunlight and re-radiate it at longer wavelengths directed toward the edge of the slab, where the energy is collected by a solar cell.

“The LSC serves as a light-harvesting antenna that concentrates solar radiation collected from a large area onto a much smaller solar cell, and this increases its power output,” the lead researcher explained. In tests using large LSC slabs (sized in tens of centimeters), researchers reported harvesting photons at roughly 10 percent efficiency. Typical photovoltaic solar panels have an average efficiency of about 15 percent.