Nickel-Cathoded Perovskite Solar Cells

Current lead halide perovskite solar cells use high work function (φ) precious metals, such as gold (φ = 5.1 eV), as the back cathode to maximize the attainable photovoltage. We report herein a set of perovskite-type solar cells that use nickel (φ = 5.04 eV), an earth-abundant element and non-precious metal, as back cathode and achieve the same open-circuit voltage as gold and an efficiency of 10.4%. This work opens a “nickel”-and-dimed (low-cost) way toward high-efficient perovskite solar cells.