Two simple hole-transporting materials for perovskite solar cells: A DFT calculation and experimental study

• The effect of the modulated core on the properties of HTMs and PSCs was explored. • Two HTMs of biphenyl core-based HY5 and pyrene core-based HY6 were designed. • Pyrene core-based HY6 exhibits better planarity and higher hole mobility than HY5. • The HY6-based devices are higher efficiency than that of Spiro-OMeTAD. • Rational extension of π-bridge is an effective strategy to design potential HTMs. Rational design of hole transport materials (HTMs) is an important way to improve the performance of perovskite solar cells (PSCs). In this work, on basis of the biphenyl and pyrene cores, two methoxyaniline derivatives-based HTMs of HY5 and HY6 have been designed, aiming to explore the influence of the modulated π-bridged cores on the properties of HTMs and the performances of PSC devices. On basis of DFT and TD-DFT combined with Marcus theory, the computational results show the pyrene core endows HY6 with a more planarity and stronger conjugation than the biphenyl core of HY5 , which promotes the delocalization of π electrons and the π–π stacking for improvement of the hole transporting. Therefore, the HY6 -based device achieved a power conversion efficiency (PCE) (19.34%) superior to the HY5 (15.50%) and Spiro-OMeTAD (18.33%) based devices. Conclusively, rational modulation of π-bridge conjugation is a feasible strategy to obtain the potential HTMs for improvement of the PSCs performance.