Simulated photovoltaic performance of N719 ruthenium dye sensitised solar cell with a power conversion efficiency exceeding 26% based on electron transport double layer

, and a fill factor (FF) of 86.66%. The relative permittivity of the materials used in heterojunction solar cells is often overlooked during the design of new material combinations. This work challenges this approach by studying the impact of permittivity on the physics and performance of solar cells through numerical simulations supported by analytical relationships. The results show that, depending on the cell configuration and material properties, the relative permittivity can have a significant effect on conversion efficiency, though its influence may sometimes be ignored without notable consequences. This work demonstrates that high permittivity materials should be prioritized as partners in the heterojunction with the absorber layer. The present configuration makes solar cells more robust against non-idealities, which are likely to occur in the early stages of development before full optimization of the device is realized.