Control of Charge Dynamics through a Charge‐Separation Interface for All‐Solid Perovskite‐Sensitized Solar Cells

Abstract

The relationship between the structure of the charge‐separation interface and the photovoltaic performance of all‐solid dye‐sensitized solar cells is reported. This cell is composed of porous a TiO₂/perovskite (CH₃NH₃PbI_xCl_3−x)/p‐type organic conductor. The porous titania layer was passivated with Al₂O₃ or Y₂O₃ to remove surface traps of the porous titania layer. Both passivations were effective in increasing the efficiency of the solar cell. Especially, the effect of Y₂O₃ passivation was remarkable. After passivation, the efficiency increased from 6.59 to 7.5 %. The increase in the efficiency was discussed in terms of the electron lifetime in TiO₂, the thermally stimulated current, the measurement of the microwave refractive carrier lifetime, and transition absorption spectroscopy. It was proven that surface passivation resulted in retardation of charge recombination between the electrons in the porous titania layers and the holes in the p‐type organic conductors.