Perovskite‐Compatible Carbon Electrode Improving the Efficiency and Stability of CsPbI2Br Solar Cells

Carbon electrodes are a promising alternative to metal electrodes in the access of high‐stable and low‐cost perovskite solar cells (PSCs). However, polar components (including cyclohexanone, terpineol, etc.) in commercial carbon pastes for carbon electrodes usually corrode perovskite materials, thereby deteriorating the photovoltaic performance of the resulting solar cells. Therefore, the development of perovskite‐compatible carbon pastes and carbon electrodes is of great significance in obtaining high‐performance carbon‐based PSCs. Herein, carbon pastes based on low polar alkane solvents are developed for perovskite‐compatible carbon electrode (PCCE) in the construction of carbon‐based CsPbI2Br PSCs. The optimized cells based on PCCE offer a champion efficiency of 13.16% (JSC = 14.33 mA cm−2, VOC = 1.22 V, and fill factor (FF) = 0.75), which is remarkably higher than that of commercial carbon paste‐derived counterparts (11.51%). Even without encapsulation, CsPbI2Br PSCs based on PCCE maintain over 93% of their initial efficiency in an air atmosphere with a humidity of 30–40% for over 1000 h. A novel perovskite‐compatible carbon electrode based on low polar alkane solvent decreases the defect at CsPbI2Br/carbon interface and hinders moisture in the atmosphere. The champion device obtains a power conversion efficiency (PCE) of 13.16% and provides outstanding stability with a PCE maintaining 93% of the initial value after 1000 h under a humidity of 30–40% without additional encapsulation.