Spongy carbon film deposited on a separated substrate as counter electrode for perovskite-based solar cell

A conceptually new carbon counter electrode for perovskite solar cell was demonstrated, which was fabricated on a separated substrate and then assembled with other components to complete a whole device, in contrast to conventional metal or carbon electrodes which are directly deposited on other component layers of the device. Power conversion efficiency (PCE) of 4.24% was achieved for perovskite solar cell with an optimized carbon electrode. The separation of preparation of electrode and device assembly provides much freedom for the choices of materials and preparation process to fabricate the device.