Pyrene Core-based Dopant-free Hole Transporting Materials for Perovskite Solar Cells: A Theoretical Design and Experimental Verification

Hole transport materials (HTMs) are an indispensable part of perovskite solar cells (PSCs), and the role of HTMs in improving the performance of PSCs is worth highlighting. In this work, an efficient triphenylamine-based HTM (HY4) is constructed by introducing a fused aromatic core. Theoretical calculated results reveal that the introduced pyrene core in HY4 with a better planarity than the parental HTM (H101 is conducive to promote the intermolecular pi-pi stacking and reduce the reorganization energy in the hole transferring process. Experimental characterization further confirms that HY4 exhibits matched energy levels, high hole mobility, smooth film morphology, and extraordinary hole extraction ability. Therefore, dopant-free HY4-based PSC devices can achieve a higher power conversion efficiency of 16.62% than a dopant-free H101-based device (14.92%). This work demonstrates that incorporating a fused aromatic core in HTMs is a promising strategy to improve device performance.

Automated summary

This study successfully constructed an efficient triphenylamine-based HTM (HY4) and demonstrated its potential in improving the performance of PSCs. The introduced fused aromatic core in HY4 enhances molecular stacking effects, reduces reorganization energy in hole transfer, leading to excellent performance in electron energy levels, charge carrier mobility, film morphology, and hole extraction capability.