Enhancing perovskite solar cell performance through dynamic hydrogen-mediated polarization of nitrogen and sulfur in phthalocyanine

Perovskite defect passivation has been researched extensively as an essential technique to improve the efficiency and stability of perovskite solar cells (PSCs) and thus drive their future commercialization. Three phthalocyanines named NP-SC6-ZnPc, NP-SC6-CuPc, and NP-SC6-H2Pc were synthesized and use for PSCs passivation. Theoretical calculations and experimental verifications confirmed that NP-SC6-H2Pc had the best passivation effect on perovskites. The phthalocyanine ring’s central hydrogen atoms are transferred dynamically from NP-SC6-H2Pc and interact with the formamidinium lead iodide (FAPbI3) perovskite through nitrogen-hydrogen bonding, resulting in α-FAPbI3 perovskite formation and increasing the sulfur/nitrogen (S/N) passivation capability. FAPbI3-based PSCs treated with NP-SC6-H2Pc demonstrated the highest power conversion efficiency (PCE) of 24.03% (certified PCE of 23.78%) with excellent stability. This significant finding represents the first observation of dynamic transfer of the hydrogen atoms in phthalocyanine and provides a thorough investigation of the perovskite passivation mechanism.