Quasi-2D lead-free halide perovskite using superalkali cations for red-light-emitting diodes

Two dimensional halide perovskites have attracted intense attention, but there is no study to consider quasi-2D lead-free perovskites with superalkali cations as potential emitting materials. Herein, the quasi-2D [C₆H₅(CH₂)₂NH₃]₂H₅O₂Sn₂Br₇ perovskite is systematically studied by using ab initio molecular dynamics simulation and first principles calculations. The calculated results show that the quasi-2D perovskite has negative formation energy, small effective hole and electron masses, stable dynamics performance, suitable exciton binding energy and direct band gap, and H₅O₂ superalkali cations that don't agglomerated. Moreover, the band-edge states do not change for the quasi-2D perovskite after ab initio molecular dynamics simulation of 3 ps. Overall, our results indicated that the quasi-2D [C₆H₅(CH₂)₂NH₃]₂H₅O₂Sn₂Br₇ perovskite may be applied to red-light-emitting diodes.