The first solar cell with an external quantum efficiency (EQE) that exceeds 100 percent for photons with energies in the solar range has been created. With these new solar cells, every blue photon that is absorbed can generate up to 30 percent more current than with current technologies.
The external quantum efficiency is the measure of how many photons are converted into electrons within a device.
“While traditional semiconductors only produce one electron from each photon, nanometer-sized crystalline materials such as quantum dots avoid this restriction and are being developed as promising photovoltaic materials,” an AVS news release notes. “An increase in the efficiency comes from quantum dots harvesting energy that would otherwise be lost as heat in conventional semiconductors. The amount of heat loss is reduced and the resulting energy is funneled into creating more electrical current.”