2D/3D perovskite hybrids as moisture-tolerant and efficient light absorbers for solar cellsElectronic supplementary information (ESI) available: Synthesis procedures, device construction and characterisation details. See DOI: 10.1039/c6nr04741f

The lifetime and power conversion efficiency are the key issues for the commercialization of perovskite solar cells (PSCs). In this paper, the development of 2D/3D perovskite hybrids (CA 2 PbI 4 /MAPbI x Cl 3− x ) was firstly demonstrated to be a reliable method to combine their advantages, and provided a new concept for achieving both stable and efficient PSCs through the hybridization of perovskites. 2D/3D perovskite hybrids afforded significantly-improved moisture stability of films and devices without encapsulation in a high humidity of 63 ± 5%, as compared with the 3D perovskite (MAPbI x Cl 3− x ). The 2D/3D perovskite-hybrid film did not undergo any degradation after 40 days, while the 3D perovskite decomposed completely under the same conditions after 8 days. The 2D/3D perovskite-hybrid device maintained 54% of the original efficiency after 220 hours, whereas the 3D perovskite device lost all the efficiency within only 50 hours. Moreover, the 2D/3D perovskite hybrid achieved comparable device performances (PCE: 13.86%) to the 3D perovskite (PCE: 13.12%) after the optimization of device fabrication conditions. 2D/3D perovskite hybrids achieved significantly improved moisture stability and analogical device performances as compared with homogeneous 3D perovskites.