Tailored interface molecules for modulating charge carrier dynamics in perovskite solar cells

Interface engineering has been confirmed as an effective strategy for optimizing charge carrier dynamics of perovskite solar cells, while the design of modulators is a crucial to achieving significant interface effects. In this study, dimethyl 2,5-dihydroxyterephthalate (PEOH), dimethyl 2,5-dibromo-3,6-dioxocyclohexa-1,4-diene-1,4dicarboxylate (QEBr) and dimethyl 2,5-dibromo-3,6-dihydroxyterephthalate (PEOH-Br) are synthesized and introduced into the interface between perovskite layer and hole transport layer to modulate the energy level match and passivate interfacial defects. Theoretical calculation and experimental results indicate that PEOH exhibits the best modulating effect, which effectively minimize the charge carrier loss and energy loss in the photovoltaic conversion process of PSCs. Benefited from this interfacial modulation, the PEOH modified device yields an impressive efficiency of 25.26 % with the enhanced open-circuit voltage of 1.176 V, much higher than the efficiency of 23.11 % for the pristine device, along with excellent operation stability. This study proves the reliability of the oriented synthesis interface materials and provides valuable insights for the efficient selection and utilization of interface materials.