Effect of local crystal field environment on luminous properties of Er3+/Yb3+-doped titanate upconversion luminescent materials

Abstract

The upconversion luminescence performance is closely related to the local crystal field environment. However, it is challenging to achieve an ideal luminescence performance by local crystal structure engineering. In this work, four titanate upconversion luminescent materials with fixed elemental compositions were synthesized, which enabled systematic exploration effects of the local crystal field environment (local structure symmetry and interatomic distance) on the upconversion performance. When the effects of local structure symmetry and interatomic distance on upconversion performance were taken into account individually, it was not easy to precisely characterize how the local crystal field environment influenced the upconversion performance. Thus, to illustrate this issue, we established a mathematical model that can satisfactorily describe the variation trend of the red/green integrated intensity ratio in terms of the product of local crystal field intensity and interatomic distance. This finding provides an excellent theoretical basis for the design of luminescent materials with ideal upconversion performance.