The influence of electrode for electroluminescence devices based on all-inorganic halide perovskite CsPbBr₃

Electroluminescence devices based on all-inorganic halide perovskite material with excellent luminescence performance have been studied extensively in recent years. However, the important role for the electrodes of electroluminescence devices is payed few attention by theoretical and experimental studies. Appropriate electrodes can reduce the Schottky barrier height to decrease the energy loss, and prevent the metal impurities from diffusing into the perovskite material to generate deep traps levels, which improves the luminous efficiency and lifetime of devices. In this paper, not only the interface effects between CsPbBr₃ and common metal electrode (Ag, Au, Ni, Cu and Pt) are studied by first-principle calculations, but also the diffusion effects of metal electrode atom into the CsPbBr₃ layer are also explored by nudged elastic band calculations. The calculated results show the metal Ag is more suitable for the cathode for CsPbBr₃ electroluminescence devices, while the metal Pt is more applicable for the anode. Based on the overall consideration about the interface effects and diffusion effects of the CsPbBr₃-metal electrode junctions, the essential principle is analyzed. The work provides theoretical guidance for how to select the right electrode for the electroluminescence performance of all-inorganic halide perovskite. The critical factor of Schottky barrier height between the electrode and the light-emitting semiconductor, and transition level generated by metal impurities also provide a valuable reference how to select the suitable electrodes for other electroluminescence devices. (paper)