Enhanced photovoltaic performance of perovskite CH₃NH₃PbI₃ solar cells with freestanding TiO₂ nanotube array films.

Freestanding TiO2 nanotube array films are fabricated and first applied as electrodes in perovskite CH3NH3PbI3 sensitized solar cells. The device demonstrates improved light absorption with more than 90% of light absorbed in the whole visible range and a reduced charge recombination rate, leading to a significant improvement of the photocurrent and efficiency. This study suggests a promising way of improving the conversion efficiency of perovskite solar cells through novel electrodes.