Improving the operational stability of perovskite solar cells with cesium-doped graphene oxide interlayer

Perovskite solar cells (PSCs) have made great advances in terms of power conversion efficiency (PCE), yet their subpar stability continues to hinder their commercialization. The interface between the perovskite layer and the charge-carrier transporting layers plays a crucial role in undermining the stability of PSCs. In this work, we propose a strategy to stabilize high-performance PSCs with PCE over 23% by introducing a cesium-doped graphene oxide (GO-Cs) as an interlayer between the perovskite and hole-transporting material. The GO-Cs treated PSCs exhibit excellent operational stability with a projected T80 (the time where the device PCE reduces to 80% of its initial value) of 2143 hours of operation at the maximum powering point under one sun illumination.