Analytical model for interface recombination limited ideality factors in p-i-n perovskite solar cells

Perovskite solar cells have emerged as a promising thin-film solar cell technology. However, compared to state-of-the-art photovoltaic technologies, perovskite solar cells still suffer from large nonradiative recombination losses. A dominant nonradiative recombination channel is recombination taking place at the interfaces between the perovskite active layer and the charge carrier transport layers. In this work, the influence of nonradiative interface recombination on the open-circuit voltage and the ideality factor in p-i-n type perovskite solar cells is clarified. We derive analytical expressions for the open-circuit voltage and the ideality factor. The analytical framework is substantiated by numerical drift-diffusion simulations. For devices dominated by interface recombination at the perovskite/transport layer interface, it is found that the open-circuit voltage is limited by the electrical potential loss across the charge transport layer. As a result, the corresponding ideality factor becomes dependent on the dielectric properties of the charge transport layers. These findings suggest that the voltage loss and ideality factor can be reduced by manipulating the thickness and dielectric properties of the charge transport layers.