Long persistent phosphor SrZrO3:Yb3+ with dual emission in NUV and NIR region: A combined experimental and first-principles methods

A dual-emission long persistent luminescence phosphor SrZrO3: Yb3+ is synthesized through a conventional high-temperature solid-state reaction method. A combined experiment and first-principles methods are carried out to study the inner link between the electronic structures and spectroscopic characteristics of SrZrO3: Yb3+ phosphor. The calculation shows that the incorporation of Yb3+ ions into SrZrO3 lattice can be done through substituting Yb3+ ions for Sr site. It is found that vacancy defects of SrZrO3: Yb3+ system easily produce around the doping positions. Especially, the oxygen vacancies, which are deduced as the intrinsic vacancy defect, are responsible for the persistent luminescence in SrZrO3: Yb3+ phosphor. The persistent luminescence of SrZrO3: Yb3+ consists of two parts: near-ultraviolet persistence originate from self-trapped excitons of host, and near-infrared one stems from 2F5/2 → 2F7/2 transitions of Yb3+. The photoluminescence and persistent performance are studied as function of the concentration of Yb3+ ions. The optimal concentration of Yb3+ ions for the photoluminescence emission and long persistent luminescence are both approximately 2.5%. The long persistent luminescence mechanism for SrZrO3:Yb3+ is illuminated on the basis of photoluminescence and first-principle calculation results.