Double decker

Interesting work at EMPA, the Swiss Federal Laboratories for Materials Science and Technology, where they have enhanced overall conversion efficiencies by stacking two different solar cells on top of each other. The upper, perovskite based, solar cell is semi-transparent with the lower cell made from copper indium gallium diselenide. The upper cell absorbs and converts the blue and yellow spectrum of visible light leaving the visible red and infrared radiation to transmit through for absorption by the lower cell.