Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency

Michael Saliba,^‡*ab Taisuke Matsui,^‡c Ji-Youn Seo,^a Konrad Domanski,^a Juan-Pablo Correa-Baena,^d Mohammad Khaja Nazeeruddin,^b Shaik M. Zakeeruddin,^a Wolfgang Tress,^a Antonio Abate,^a Anders Hagfeldt^d and Michael Gräzel^a

^‡ These authors contributed equally.
^a Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
^b Group for Molecular Engineering of Functional Materials, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, Sion CH-1951, Switzerland
^c Advanced Research Division, Materials Research Laboratory, Panasonic Corporation, 1006 Kadoma, Kadoma City, Japan
^d Laboratory of Photomolecular Science (LSPM) École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland

DOI: 10.1039/C5TA04904K.
First published online 27 Aug 2015
Paper on RSC website
Paper in open access repository (europepmc)
Paper in open access repository (infoscience)

Today’s best perovskite solar cells use a mixture of formamidinium and methylammonium as the monovalent cations. With the addition of inorganic cesium, the resulting triple cation perovskite compositions are thermally more stable, contain less phase impurities and are less sensitive to processing conditions. This enables more reproducible device performances to reach a stabilized power output of 21.1% and B18% after 250 hours under operational conditions. These properties are key for the industrialization of perovskite photovoltaics.