...and a group headed by Prof. Michael Graetzel at the École Polytechnique Fédérale de Lausanne (EPFL) are the first to have fabricated this kind of monolithic tandem cell
A silicon heterojunction solar cell has been successfully combined with a perovskite solar cell monolithically into a tandem device, for the first time, report scientists. The hybrid tandem cell showed an efficiency of 18 percent. That is the highest currently reported value for this type of device architecture. There are even prospects for the efficiency to reach as much as 30 percent.