Chinese scientists said they have come up with a more efficient luminescent solar concentrator (LSC), which can be applied on “solar windows” to turn sunlight into electricity.
Researchers at the Dalian Institute of Chemical Physics said they designed a “quantum-cutting” approach to double the efficiency of LSC devices. Their research has been published in the December issue of Nano Letters.
LSC, a less expensive photovoltaic technology, functions by collecting sunlight on a broad area, converting it into luminescence and directing it to solar cells that are squeezed into the narrow edge. Their semitransparent appearance also allows for creating “solar windows” that can turn energy-consuming buildings into power-generation units.
Traditional LSC designs, however, have been plagued by a low internal optical efficiency, usually lower than 60 percent, caused partially by a loss of energy to self-absorption, said Wu Kaifeng, who leads the research team.
Wu’s team used ytterbium-doped nanocrystals to make the new LSC based on the concept of quantum cutting, or cutting one photon into two while conserving the total energy. The new materials emit two near-infrared photons after absorbing one blue photon, achieving an internal optical efficiency of about 120 percent.