Asymmetric phthalocyanine-based hole-transporting materials: evaluating the role of heterocyclic units and PMMA...

Two novel asymmetric phthalocyanine derivatives, ZnPc-1 and ZnPc-2, are synthesized to enhance charge transfer properties and mitigate deep-level traps on the perovskite surface using electron-rich nitrogen atoms. PSCs with ZnPc-1 and ZnPc-2 as hole-transporting materials (HTMs) achieved power conversion efficiencies (PCEs) of 12.11% and 8.98%, respectively. Incorporating a small amount of PMMA into the HTM solution significantly improved performance, resulting in PCEs of 16.2% and 12.5% for ZnPc-1 and ZnPc-2, respectively. The addition of PMMA enhances conductivity and prevents moisture intrusion, boosting both the efficiency and stability of PSCs.