Spontaneous Radiative Cooling to Enhance the Operational Stability of Perovskite Solar Cells via a Black-body-like Full Carbon Electrode

Abstract Operational stability of perovskite solar cells is remarkably influenced by the device temperature, therefore, decreasing the interior temperature of the device is one of the most effective approaches to prolong the service life. Herein, we introduce the spontaneous radiative cooling effect into the perovskite solar cell and amplify this effect via functional structure design of a full-carbon electrode (F-CE). Firstly, by the aid of interfacial engineering, >19% and >23% power conversion efficiencies of F-CE based inorganic CsPbI 3 and hybrid perovskite solar cells have been achieved, respectively, both of which are the highest reported efficiencies based on carbon electrode and are comparative to the results for metal electrodes. Highly efficient thermal radiation of this F-CE can reduce the temperature of the operating cell by about 10°C. Compared with the conventional metal electrode-based control cells, the operational stability of the above two types of cells have been significantly improved due to this cooling effect. Especially, the CsPbI 3 PSCs exhibited no efficiency degradation after 2000 hours continuous operational tracking. One-Sentence Summary: Thermal radiative cooling effect of full-carbon electrode enhances operational stability of the perovskite solar cells.