3,4-Dihydroxybenzhydrazide as an additive to improve the morphology of perovskite films for efficient and stable perovskite solar cells

Morphological engineering plays a very important role to the performance of perovskite solar cells. In this study, 3,4-dihydroxybenzhydrazide employes as an additive in the perovskite precursor to control the crystallization kinetics. It is found that the doping of 3,4-dihydroxybenzhydrazide led to increase of grain size and decrease of grain boundaries, both of which facilitate charge transportation and suppress charge recombination within the photoactive layers. Consequently, the power conversion efficiencies of the corresponding perovskite solar cells are significantly enhanced, and a champion power conversion efficiencies of 17.58% with open circuit voltage of 1.06 V, short circuit current density of 21.40 mA cm−2 and fill factor of 79.1% is achieved, which is 21.5% higher than that without 3,4-dihydroxybenzhydrazide (14.47%). Moreover, upon doping the stability of the perovskite solar cells is also improved. We believe that the idea demonstrated in this research can also be applied to other lead-based perovskite systems.