Optimizing Perovskite Solar Cells by Understanding the Bulk Properties of Contact Layers

Along with optimizing perovskite-contact interfaces is the need to optimize the bulk contact properties in relation to passivation, selectivity, and conductivity. In this work, we investigate the thickness-dependence of the implied-JV, pseudo-JV, and JV curves for devices made with different perovskite contact layers. We are able to extract from these curves selectivity
$(\boldsymbol{V}_{oc}/iV_{oc})$
, series resistance, efficiencies, and fill factors in order to demonstrate the reasons for optimal device performance and to offer paths forward for improving each contact. Additionally, we show the spatial variance of
$\boldsymbol{i}\boldsymbol{V}_{oc}$
of perovskite grown on top of hole contact layers to demonstrate the effects of this variation on final device performance.