Spectacular Enhancement of Pr3+ Emission in a Highly Symmetric Ba2MgWO6 Matrix

Abstract

Double perovskite materials have recently attracted a lot of attention from the scientific community studying luminescent materials for white light-emitting diodes (WLEDs), displays, and luminescence thermometry. A series of Pr3+-doped Ba2MgWO6 (BMW) powder samples were prepared by two different synthesis methods: coprecipitation (C-P) method and conventional high-temperature solid-state reaction method (S-S), as a material to improve the quality of white LED lighting, and their structural and spectroscopic properties are described in detail. We assumed that obtaining them by the conventional solid-state method would significantly improve their spectroscopic properties. The results are clear and prove that by replacing the coprecipitation method with the solid-state method, we can obtain a better material for WLED lighting. This is because when a W6+ ion replaces the Mg2+ site in the BMW structure, a defect is created resulting in an excess of quadruple positive charge of the W6+ ions at the Mg2+ position, expressed as (WMg6+)• in Kröger-Vink notation. The C-P method generates many more of these defects due to the larger active surface area of these samples compared to the S-S samples. We observed that a decrease in the number of defects (WMg6+)•••• correlates with a weaker intervalence charge transfer (IVCT) band and, consequently, a stronger emission of Pr3+ ions in the BMW material synthesized by the solid-state method. The use of BMW:Pr3+ material has the potential to improve the quality of white light. According to simulations, the CRI parameter could be elevated from 85 to 95.