Fully Solution-Processed n–i–p-Like Perovskite Solar Cells with Planar Junction: How the Charge Extracting Layer Determines the Open-Circuit Voltage

Fully solution-processed direct perovskite solar cells with planar junction are realized by incorporating a cross-linked [6,6]-phenyl-C61-butyric styryl dendron ester layer as an electron extracting layer. Power conversion efficiencies close to 19% and an open-circuit voltage exceeding 1.1 V with negligible hysteresis are delivered. A perovskite film with superb optoelectronic qualities is grown, which reduces carrier recombination losses and hence increases V _oc.