Unveiling the Mechanism of Rare Earth Doping to Optimize the Optical Performance of CsPbBr3 Perovskite
Rare-earth (RE) doping is one of the valid approaches to optimized the optical performance of CsPbBr3 perovskite. However, the underlying mechanism and the role of RE_4f electrons are still unknown, which are full of significance for the development of advanced RE-doped perovskite materials. Considering these, a series of CsPbBr3:RE (RE = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) compounds are studied by applying first-principles calculations. Based on the analysis of phase stability diagram, we find that RE doping in CsPbBr3 bulk leads to form REPb defect. Meanwhile, the two types of electric-dipole allowed transition are figured out by exploring the electronic structure. We also demonstrate that the doped systems retain the defect tolerance nature of host and the RE_4f electrons enrich the band-edge states, which are the main origins for luminescence enhancement. Our current contribution not only presents physical insight into understanding of RE_4f role in luminescence, but also provides a guideline for designing the targeted RE-doped perovskites.