Fully functional semi-transparent perovskite solar cell fabricated in ambient air

Organic-inorganic halide perovskite has excellent properties to function as light harvesters in solar cells due to the possibility to tune its optical properties and to use it as thin film absorber, at a few hundred-nanometer thicknesses. Herein, we demonstrate the fabrication of perovskite solar cells with controlled transparency, by the mesh assisted deposition process. Sequential fabrication of perovskite was performed in air, wherein a PbI₂ grid was formed in the first step, and in the second step, the grid reacted selectively with methylammoniumiodide, resulting in a perovskite grid pattern. The best cells were obtained with a photoanode composed of mesoporous TiO₂ with Al₂O₃ nanoparticles. The resulting semi-transparent perovskite solar cells, including a semi-transparent contact composed of MoO₃/Au/MoO₃ yielded a power conversion efficiency of 5.5% with an average transparency of 26% and efficiency of 8% for cells fabricated with a gold contact.