Abstract
Fully printable hole transport layer-free mesoscopic perovskite solar cells have proven excellent long-term stability and are therefore promising candidates for scale-up to larger modules required for the commercialization of the perovskite photovoltaic technology. In this work the imbalanced charge extraction resulting from relatively thick device architectures is addressed by adding CuSCN to the perovskite absorber layer which was shown to significantly reduce the hysteresis and improve solar cell efficiency.