Abstract
Fast crystallization growth in thin‐film photovoltaic materials, often associated with solution‐based low‐cost processing, induces crystal misorientation defects called grain boundaries. Grain boundaries are generally believed to be sources of efficiency losses in photovoltaics, but their impact in halide perovskite materials is not at all trivial. Herein, a semianalytical model is proposed that leverages the standard rate equation to elucidate the microscopic impact of grain boundaries in halide perovskites. Grain boundary and surface recombination can have different impacts up to 3 orders of magnitude to carrier lifetime and quasi‐Fermi‐level splitting. Variation in grain sizes can play a greater role than the average grain size, leading to a 2% drop in photovoltaics efficiency. Heteroscedasticity in grain variation is even more problematic for large grains, which explains why samples with small grains may perform better than larger ones. A map of the power conversion efficiency of individual grains is simulated, showing that recombination current exchange among adjacent grains reduces the overall efficiency by 4%, depending on their spatial arrangement. Although carrier transport is uniquely dictated by the characteristics of grain boundaries, the generalized scheme presented herein should be useful for accommodating more complexity beyond simply the grain size effect.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call