Three-dimensional lead iodide perovskites based on complex ions

Abstract

Lead-halide perovskites have demonstrated outstanding optical, electrical, and spintronic properties and have made significant breakthroughs in many fields, especially in solar cells. Although substantial efforts have been devoted to developing novel 3D perovskites with a lower band gap towards the application in perovskite solar cells, none of them succeeded. Here we propose three novel 3D lead iodide perovskites with complex ions, Cu(NH₃)₂PbI₃, Ag(NH₃)₂PbI₃ and Au(NH₃)₂PbI₃. Based on the optimized structures, formation and dissociation energies, phonon spectra, and ab initio molecular dynamics simulations, it is found that Ag(NH₃)₂PbI₃ and Au(NH₃)₂PbI₃ are kinetically and thermodynamically stable. Furthermore, Ag(NH₃)₂PbI₃ and Au(NH₃)₂PbI₃ exhibit large absorption coefficients, suitable optical band gaps and small electron effective masses, which are very promising towards application in perovskite solar cells.