Enhancing the Optoelectronic Performance of Perovskite Solar Cells via a Textured CH₃NH₃PbI₃ Morphology

Perovskite-based solar cells are generally assembled as planar structures comprising a flat organoammonium metal halide perovskite layer, or mesoscopic structures employing a mesoporous metal-oxide scaffold into which the perovskite material is infiltrated. To present, little attention has been directed toward the texturing of the perovskite material itself. Herein, a textured CH₃NH₃PbI₃ morphology formed through a thin mesoporous TiO₂ seeding layer and a gas-assisted crystallization method is reported. The textured morphology comprises a multitiered nanostructure, which allows for significant improvements in the light harvesting and charge extraction performance of the solar cells. Due to these improvements, average short-circuit current densities for a batch of 28 devices are in excess of 22 mA cm^-2, and the maximum recorded power conversion efficiency is 16.3%. The performance gains concomitant with this textured CH₃NH₃PbI₃ morphology provide further insights into how control of the perovskite microstructure can be used to enhance the cell performance. A textured CH₃NH₃PbI₃ morphology for perovskite-based solar cells is presented. The textured morphology exhibits enhanced light harvesting and charge separation properties. The highest measured power conversion efficiency is 16.3%.