Light-activated interlayer contraction leads to high-efficiency in 2D perovskite solarcells

National audience; Despite their improved stability and versatility, 2D layered perovskites’ solar cell efficiencies lag behind those of their 3D counterparts, which currently exceed 25%. Through a proper selection of the organic spacer, 2D perovskites can be synthetized in different configurations adopting various phases such as the Ruddlesden-Popper (RP), the Alternating Cation Interlayer (ACI) or the Dion-Jacobson ones. Tailoring the organic spacer type has been shown to enhance the electronic coupling along the layered perovskite stacking axis and thereby enhance carrier transport resulting in improved efficiencies.