Core Fusion Engineering of Hole-Transporting Materials for Efficient Perovskite Solar Cells

Abstract

In this work, a fused polycyclic aromatic hydrocarbon (PAH) core was introduced to construct hole-transporting materials (HTMs) for perovskite solar cells (PSCs). It was found that with the extended π-conjugation of the fused core, the hole mobility was enhanced along with the better film-forming property for (tetrakis(hexylphenyl)-dronaphthotetraphenodithiophene)bis(N,N-bis(methoxyphenyl)aniline) (MPA-DTP) compared to that for (tetrakis(hexylphenyl)-indacenodithiophene)bis(N,N-bis(methoxyphenyl)aniline) (MPA–IDT). The smooth and condensed film morphology is beneficial for interfacial contact, leading to reduced nonradiative recombination. As a result, planar PSCs based on MPA–DTP displayed a superior efficiency of 19.20%, far exceeding that of the MPA–IDT-based device (15.64%) and slightly higher than those with spiro-OMeTAD (19.11%). We believe that fused core engineering is envisioned as a promising strategy for developing highly efficient HTMs in PSCs.