Perovskite Films by Metal Additives to the Single-Step Solution Fabrication Process*

Methods of obtaining large grain size and high crystallinity in absorber materials play an important role in fabrication of high-performance methylammonium lead iodide (MAPbI₃) perovskite solar cells. Here we study the effect of adding small concentrations of Cd²⁺, Zn²⁺, and Fe²⁺salts to the perovskite precursor solution used in the single-step solution fabrication process. Enhanced grain size and crystallinity in MAPbI₃ films were obtained by using 0.1% of Cd²⁺ or Zn²⁺in the precursor solution. Consequently, solar cells constructed with Cd- and Zn-doped perovskite films show a significant improvement in device performance. These results suggest that the process may be an effective and facile method to fabricate high-efficiency perovskite photovoltaic devices.