The nominating institution Fraunhofer ISE on the breakthrough:

Standard solar cells can only convert light of a limited wavelength range optimally while other regions of the sun’s spectrum are not or poorly used. This is mainly influenced by the electronic bandgap of the absorber material. Therefore, the conversion efficiency of solar cells made from one material is limited (around 30%). By combining solar cells with different bandgaps in a tandem cell, the sun spectrum can be used much more effectively. This will be the new generation of photovoltaics.

Tags: Climate change, Energy, Green Tech.