Molecular engineering of enamine-based small organic compounds as hole-transporting materials for perovskite solar cellsElectronic supplementary information (ESI) available: Experimental procedures, theoretical calculations, device fabrication details etc. See DOI: 10.1039/c8tc06297h

The search for new classes of hole transporting materials (HTMs) is a very important task on the way towards commercialization of perovskite solar cells (PSCs). In this work, the synthesis and performance in PSCs of new enamine-based HTMs are presented. The synthesis scheme is very short, consisting of only one step, starting from commercially available aromatic amines. Moreover, the reaction does not require metal catalysts and is based on condensation chemistry with water as a by-product. It was shown that PSCs with such materials reach high power conversion efficiencies (PCE), with the highest PCE of 19% achieved for the V1021 -based device. This work establishes enamines as a very promising class of materials for application in PSCs. Optimization of the structure of hole transporting material leads to over 19% efficiency.