Benzotrithiophene-based hole-transporting materials for 18.2 % perovskite solar cells

Abstract

New star-shaped benzotrithiophene (BTT)-based hole-transporting materials (HTM) BTT-1, BTT-2 and BTT-3 have been obtained through a facile synthetic route by crosslinking triarylamine-based donor groups with a benzotrithiophene (BTT) core. The BTT HTMs were tested on solution-processed lead trihalide perovskite-based solar cells. Power conversion efficiencies in the range of 16 % to 18.2 % were achieved under AM 1.5 sun with the three derivatives. These values are comparable to those obtained with today's most commonly used HTM spiro-OMeTAD, which point them out as promising candidates to be used as readily available and cost-effective alternatives in perovskite solar cells (PSCs). Promising new candidates: Benzotrithiophenes (BTT) with different donor moieties are introduced as hole-transporting materials for perovskite solar cells. The incorporation of these new derivatives in photovoltaic devices leads to power conversion efficiencies (PCE) up to 18.2 %, thus paving the way to very efficient and highly versatile materials for light-energy conversion.