Fabrication and characterization of ethylammonium- and rubidium-added perovskite solar cells

Perovskite solar cells consist of CH₃NH₃PbI₃ perovskite crystals. The purpose of this study is to improve the conversion efficiency and stability of the perovskite solar cells by adding a small amount of ethylammonium (EA) and rubidium (Rb) to the CH₃NH₃PbI₃ compounds. Addition of ethylamine hydrobromide and rubidium iodide provided an increase in carrier concentration and promotion of crystal growth, resulting in an improvement in conversion efficiencies and stability. First-principles calculations showed that the addition of Rb lowered the total energy and made the crystal stable. The band calculation also shows that the EA addition reduces the effective mass and improves the carrier mobility.