Surface Passivation of Organic-Inorganic Hybrid Perovskites with Methylhydrazine Iodide for Enhanced Photovoltaic Device Performance

Organic-inorganic hybrid perovskites are highly efficient in photovoltaic applications, making the commercialization of perovskite solar cells (PSCs) possible. However, the high density of defects on the surface significantly affects the performance of PSCs. To address this issue, we have demonstrated a facile post-treatment strategy utilizing methylhydrazine iodide (MHyI) to passivate the surface of the perovskite film. MHyI could co-ordinate with the dangling bonds on the surface of perovskite films, effectively passivating defects in the film and suppressing carrier non-radiative recombination. As a result, PSCs with MHyI modification exhibit a champion power conversion efficiency (PCE) of 23.19% and a high open-circuit voltage (VOC) of 1.14 V (0.43 V voltage deficit). Moreover, unencapsulated solar cells maintain their initial efficiency of 88% after 30 days of exposure to ambient air with 30% humidity, and the devices with encapsulation retained 57% of their initial efficiency after 200 h of maximum power point (MPP) loading under constant light irradiation in ambient air. Overall, our results provide a facile method for improving the performance and stability of PSCs.