Rapid One‐Step Synthesis of Robust Double Perovskite La₂MgGeO₆‐Based Materials for Light Conversion

Abstract Persistent luminescence (PersL) materials attract extensive interest in the scientific community nowadays due to their great potential in various fields, such as night‐vision signage, high‐level anticounterfeiting, in vivo bioimaging, and X‐ray extension imaging. However, the majority of PersL materials are synthesized by time‐ and energy‐consuming processes such as high‐temperature solid‐state reactions or hydrothermal synthesis. In this work, a rapid one‐step microwave‐assisted solid state (MASS) synthesis of La₂MgGeO₆‐based robust double perovskite PersL material is successfully achieved, without any secondary thermal treatment, which limits the total synthesis time to 30 min. Furthermore, this MASS approach is also employed to integrate multimodal luminescence into one single La₂MgGeO₆ matrix with triple dopants (Mn⁴⁺, Yb³⁺, and Er³⁺) for light conversion. Impressively, multimodal and multicolor luminescence is obtained with different responsiveness of external stimulations. Notably, the energy transfer among different trapping levels is observed upon photo‐stimulation. This work provides a good example of the feasibility of MASS method to prepare luminescent materials with abundant optical features in an efficient, sustainable, environmentally friendly, and easily manageable way.