FlexSolar - "Highly Efficient and Flexible Thin Film Crystalline Silicon - Perovskite Tandem Solar Cells" (PTDC/CTM-REF/1008/2020) is a project funded by Portugal's FCT - Fundação para a Ciência e a Tecnologia, I.P./MCTES through national funding (PIDDAC).

The project's goal is to develop highly efficient (η>24%) ultrathin flexible epitaxial-c-Si/perovskite (2 to 12 μm thick) 4 terminal tandem solar cells.

The project is aligned with several of the United Nation's Sustainable Development Goals (SDGs), namely SDG 7 - Affordable and Clean Energy, SDG 11 - Sustainable Cities and Communities, and SDG 13 - Climate Action, as well as with those of the EU's European Green Deal.

The project's main contractor is Instituto de Desenvolvimento de Novas Tecnologias (UNINOVA) and the main research unit is the Institute for Nanostructures, Nanomodelling and Nanofabrication (i3N). The project counts on the participation of Universidade de Aveiro (UA).