Molecular Design of Hole-Collecting Materials for Co-Deposition Processed Perovskite Solar Cells: A Tripodal Triazatruxene Derivative with Carboxylic Acid Groups.

High-performance and cost-effective hole-collecting materials (HCMs) are indispensable for commercially viable perovskite solar cells (PSCs). Here, we report an anchorable HCM composed of a triazatruxene core connected with three alkyl carboxylic acid groups (). In contrast to the phosphonic acid-containing tripodal analog (), molecules can form a hydrophilic monolayer on a transparent conducting oxide surface, which is beneficial for subsequent perovskite film deposition in the traditional layer-by-layer fabrication process.

Mixed lead-tin perovskite films with >7 μs charge carrier lifetimes realized by maltol post-treatment.

Mixed lead-tin (Pb-Sn) halide perovskites with optimum band gaps near 1.3 eV are promising candidates for next-generation solar cells. However, the performance of solar cells fabricated with Pb-Sn perovskites is restricted by the facile oxidation of Sn(ii) to Sn(iv), which induces self-doping.