Carbazole-substituted NP-based derivative as hole transporting material for highly efficient perovskite solar cells

Three new organic hole transport materials (HTMs), 2, 3 and 4, are designed with NP-core along with bis(4-methoxyphenyl)amine, p-methoxytriphenylamine, and 9-p-tolyl-9H-carbazole as side group on the basis of reported HTM NP2 (1), respectively. For isolated molecules, frontier molecular orbitals, absorption and emission spectra, and hole mobility are evaluated by density functional theory (DFT) and molecular dynamics simulations. In addition, the following properties, hydrophobility, solubility, and glass transition temperatures (T_g), related with the overall performance of devices are also calculated. The HTM@CH₃NH₃PbI₃ adsorbed system is investigated to consider the effect of interfacial properties between HTM and CH₃NH₃PbI₃ on HTM properties. Our theoretical results indicate that the new designed molecule 4 has better properties than 1. More importantly, 1 has been fabricated in perovskite solar cells (PSCs) as a HTM with the power conversion efficiency of 16.4%. It is reasonable to infer that the new designed molecules would be potential candidates.