Integrated perovskite solar capacitors with high energy conversion efficiency and fast photo-charging rate

Integrating energy harvesting devices with energy storage systems can realize a temporal buffer for local power generation and power consumption. In this manner, self-charging energy devices consisting of photovoltaic cells and energy storage units can serve as sustainable and portable distributed power sources that can concurrently generate and store electric energy without the need for external charging circuits. Herein, an integrated perovskite solar capacitor (IPSC) was realized by combining a perovskite solar cell (PSC) and a supercapacitor in a single device. Taking advantages of nanocarbon electrodes, the IPSCs possess a simple configuration, compact structure, and well-matched operation voltage. The IPSCs could be rapidly charged by different modes (including the photo-charging mode, galvanostatic-charging mode, and photoassisted-galvanostatic-charging mode), and showed a remarkable overall photo-chemical-electricity energy conversion efficiency as high as 7.1% in the photo-charging mode. Moreover, the IPSCs could work efficiently under weak light illumination. This study provides new insights for the design of novel integrative energy devices that combine the functions of solar power harvesting and electrochemical energy storage.