Molecular Tailoring of Pyridine Core-Based Hole Selective Layer for Lead Free Double Perovskite Solar Cells Fabrication

To solve the toxicity issues related to lead-based halide perovskite solar cells, lead-free double Cs2AgBiBr6 is proposed. However, reduced rate of charge transfer in perovskites affects optoelectronic performance. We designed a series pyridine-based small molecules with four different arms attached pyridine core as hole-selective materials by using interface engineering. quantified how arm modulation structure–property–device performance relationship. Electrical, structural, and spectroscopic investigations show that N3,N3,N6,N6-tetrakis(4-methoxyphenyl)-9H-carbazole-3,6-diamine arm’s robust association results an efficient hole extraction for PyDAnCBZ due higher spin density close core. The cells fabricated light harvester selective layer measured unprecedented 2.9% power conversion efficiency. Our computed road map suggests achieving ∼5% efficiency through fine-tuning Cs2AgBiBr6. findings reveal principles designing electro-optical applications well synergistic route develop inorganic applications.