Based on rational combination of dibenzo[a,c]phenazine and pyridine as electronic acceptor and anchoring groups to perovskite layer, DPyP as a hole-transporting material in dopant-free PSC achieved high conversion efficiency of 20.45%, higher than that of DBP (19.77%) based on dibenzo[a,c]phenazine.

Comprehensive Summary

Perovskite solar cells (PSCs) have been proven to be a promising option for photovoltaic conversion. With the aim to achieve efficient and stable PSCs, it is essential to explore dopant-free hole-transporting materials (HTMs) with high hole mobility. Herein, HTMs bearing electron donor (D)-electron acceptor (A)-electron donor (D) structures have been constructed with strong intramolecular charge transfer (ICT) effect, based on rational combination of dibenzo[a,c]phenazine and pyridine as electronic acceptors and anchoring groups to perovskite layer. Accordingly, high hole mobility (7.31 × 10^–5 cm²·V^–1·s^–1) and photoelectric conversion efficiency (20.45%) have been achieved by dopant-free DPyP-based PSC. It afforded an efficient way to design HTMs with high hole mobility by adjustment of molecular configurations and electronic property of conjugated systems.