Photovoltaic cells currently developed to work in tandem are very unstable. With the innovative use of materials such as perovskite, these instabilities can be eliminated.

Stabilisation through the use of perovskites seems to be the most promising. However, stable, low-cost structures suitable for this type of tandem cell have never been proposed.

The ELIOS project is oriented towards a transparent carbonaceous electrode allowing the development of a tandem structure with a crystalline silicon cell. This study mixes graphene deposits and perovskite technology.