Photovoltaic solar cells based on perovskites have come to the forefront in science by achieving exceptional power conversion efficiencies (PCEs) in less than a decade of research [1]. Nowadays hole-transporting materials (HTMs) based on conductive small organic molecules have become the hottest topic in high-performance perovskite solar cells (PSCs) [2]. Star-shaped triphenylamine-phenanthreneimidazole (TPA-PIM)-based HTM has been obtained through a facile synthetic route by crosslinking phenanthreneimidazole-based donor group with a triphenylamine core (Scheme1). The incorporation of this HTM in photovoltaic devices leads to PCE up to 17 %, thus paving the way to very efficient and highly versatile materials for light-energy conversion.
