High‐Efficiency Perovskite Solar Cells Based on the Black Polymorph of HC(NH<sub>2</sub>)<sub>2</sub>PbI<sub>3</sub>
Perovskite solar cells with power conversion efficiencies exceeding 16% at AM 1.5 G one sun illumination are developed using the black polymorph of formamidnium lead iodide, HC(...