Near-infrared luminescent phosphors enabled by topotactic reduction of bismuth-activated red-emitting crystals

摘要

Bismuth-doped luminescent materials have gained significant attention in thepast years owing to their huge potential for the applications intelecommunications, biomedicine, and displays. However, the controlledsynthesis of these materials, in particular for those luminescing in thenear-infrared (NIR), remains a challenging subject of continuous researcheffort. Herein, we show that the low-temperature topotactic reduction by usingAl metal powders as oxygen getters can be adopted as a powerful technique forthe conversion of bismuth-doped red-emitting systems into NIR-emitting cousinsas a result of the creation of unique crystalline networks. Thoroughexperimental characterization indicates that the framework oxygen of hosts canbe topotactically extracted, thus producing unique metal-oxygen-metal networksin the reduced phases while preserving the crystalline structure of theprecursor. We anticipate that this low-temperature topotactic reductionstrategy can be applied to the development of more novel Bi-doped luminescentmaterials in various forms that can find a broad range of functionalapplications.