Researchers in Germany report a new world record for the conversion of sunlight into electricity using a new solar cell structure with four solar sub-cells. A new record efficiency of 44.7% was measured at a concentration of 297 suns, indicating that 44.7% of the solar spectrum’s energy, from ultraviolet through to the infrared, is converted into electrical energy. The achievement is being hailed as a major step towards reducing the costs of solar electricity.
These solar cells are used in concentrator photovoltaics (CPV), a technology which achieves more than twice the efficiency of conventional PV power plants in sun-rich locations. The terrestrial use of so-called III-V multi-junction solar cells, which originally came from space technology, has prevailed to realize highest efficiencies for the conversion of sunlight to electricity. In this multi-junction solar cell, several cells made out of different III-V semiconductor materials are stacked on top of each other. The single sub-cells absorb different wavelength ranges of the solar spectrum.