Abstract

A π-conjugated Lewis base is introduced into perovskite solar cells, namely, indacenodithiophene end-capped with 1.1-dicyanomethylene-3-indanone (IDIC), as a multifunctional interlayer, which combines efficient trap-passivation and electron-extraction. Perovskite solar cells with IDIC layers yield higher photovoltages and photocurrents, and 45% enhanced efficiency compared with control devices without IDIC.