Insight into the Characteristics of 4f-Related Electronic Transitions for Rare-Earth-Doped KLuS2 Luminescent Materials through First-Principles Calculation

摘要

Rare-earth (RE) doped ternary sulfide (KLuS2) compounds, which serve as expected X-ray phosphors and white-light-emitting diode (LED) solid-sate lighting devices, have aroused intense interest recently. However, the underlying luminescence mechanism and the rule of 4f-related electronic transition are still unknown, which are full of significance for the exploration of advanced RE-based luminescent materials. With these issues to be addressed in mind, a series of KLuS2:RE (RE = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) compounds are investigated using first-principles calculations. Based on the analysis of the equilibrium geometries and electronic structures, three types of electric-dipole-allowed transitions are revealed and three promising luminescence centers (RE = Dy, Ho, Er) are figured out. Furthermore, we have designed three new-style codoped KLuS2:Dy/Ho, KLuS2:Dy/Er, and KLuS2:Ho/Er materials to enrich the RE-doped KLuS2 family. We hope the current contribution is conducive to understanding the role of 4f in luminescent materials and provides theoretical guidelines for further preparing desired optical materials.