Efficient and Stable MAPbI₃-Based Perovskite Solar Cells Using Polyvinylcarbazole Passivation

Hybrid perovskite solar cells attract a great deal of attention due to the feasibility of their low-cost production and their demonstration of impressive power conversion efficiencies (PCEs) exceeding 25%. However, the insufficient intrinsic stability of lead halides under light soaking and thermal stress impedes practical implementation of this technology. Herein, we show that the photothermal aging of a widely used perovskite light absorber such as MAPbI₃ can be suppressed significantly by using polyvinylcarbazole (PVC) as a stabilizing agent. By applying a few complementary methods, we reveal that the PVC additive leads to passivation of defects in the absorber material. Introducing an optimal content of PVC into MAPbI₃ delivers a PCE of 18.7% in combination with a significantly improved solar cell operational lifetime: devices retained ∼70% of the initial efficiency after light soaking for 1500 h, whereas the control samples without PVC degraded almost completely under the same conditions.