In situ RbPbI3 filler for high-performance carbon-based perovskite solar cells

초록

Carbon electrode perovskite solar cells (CPSCs) are considered a promising route toward the scalable and lowcost commercialization of perovskite photovoltaics due to their simple fabrication and the avoidance of noble metal electrodes. However, poor interfacial contact between the carbon electrode and the triple-cation perovskite absorber remains a major factor limiting their power conversion efficiency (PCE). Here, we report an in situ rubidium-based perovskite (RbPbI3) interfacial filling strategy using excess PbI2 as the lead source. This strategy not only alleviates the detrimental effects of residual PbI2, but also converts it into a rubidium-based perovskite phase, thereby improving the interfacial contact between the perovskite layer and the carbon electrode. As a result, the optimized CPSCs deliver a champion PCE of 18.81%, substantially higher than that of the reference devices (14.07%). The unencapsulated modified devices also show greatly enhanced operational stability under ambient conditions (25 degrees C, 30-40% relative humidity), retaining their photovoltaic performance for nearly 300 h, whereas the untreated devices suffer rapid degradation. This work provides a reliable and scalable interfacial engineering strategy for simultaneously improving the efficiency and stability of carbon-based perovskite solar cells, further advancing their potential for practical photovoltaic applications.

키워드