Accurate and fast evaluation of perovskite solar cells with least hysteresis

It is of great importance to evaluate the performance of perovskite solar cells (PSCs) accurately, especially to avoid the errors induced by hysteresis during current density–voltage measurement. Here we found that PSCs with n–i–p and p–i–n structures exhibit very different hysteresis behavior. A longer delay time leads to small hysteresis in n–i–p PSCs, whereas it shows little effect in p–i–n ones. In contrast, a smaller voltage step is preferred for reduced hysteresis in p–i–n PSCs, which is further supported by a transient photocurrent study. Finally, we proposed fast and accurate evaluation methods for PSCs based on these two structures.