Empa researchers have achieved a new record efficiency value of 22.2% for flexible CIGS solar cells on plastic films, which has been independently confirmed by the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg.
The flexible solar cells are processed on a polymer film with Cu(In,Ga)Se2 as the light-absorbing semiconductor layer, which is deposited using a low-temperature co-evaporation process. The current increase in efficiency is due to the alloying of this layer, whose electronic properties have been improved. Flexible and lightweight solar modules with this technology are particularly suitable for applications on roofs and facades of buildings, on greenhouses, vehicles and airships as well as for portable electronics. Empa is working with the Swiss company Flisom on the roll-to-roll production of lightweight, flexible solar modules for such applications. The research was supported by the Swiss Federal Office of Energy (SFOE).
