Facile synthesis of benzotrithiophene core-based hole-transporting molecules with carbazole-wings for perovskite solar cells by Pd-catalyzed direct C-H/C-Br coupling reactions

We report herein an efficient synthetic route to two benzotrithiophene core-based hole-transporting materials bearing carbazole end-groups/wings through threefold direct C-H/C-Br cross coupling reactions under optimized Pd-catalysis. Perovskite solar cells employing individual molecule as hole-transport layer exhibited promising power conversion efficiencies of up to 17.30 %. This work provides a step-saving synthetic strategy to access star-shaped new oligoaryls and also expands the substrate scope of end-groups from triphenylamine derivatives to present carbazole-based wings.