Boosting luminescence in oxide phosphors by the vitrifying-devitrifying approach.

Area of Science:

• Materials Science
• Solid State Chemistry
• Luminescence

Background:

• Vitrification-devitrification produces glass-ceramics with properties rivaling crystalline materials.
• Europium-doped magnesium aluminum silicate (MAS:Eu) exhibits tunable luminescence.
• Europium ions (Eu²⁺) occupy multiple sites within MAS hollow channels.

Purpose of the Study:

• To investigate the impact of vitrification-devitrification on MAS:Eu luminescence.
• To enhance and tune the luminescent properties of MAS:Eu materials.
• To explore the potential of these materials for lighting devices.

Main Methods:

• Subjecting Mg₂Al₄Si₅O_18+1.5x:xEu²⁺ (MAS:xEu) powders to a vitrification-devitrification protocol.
• Analyzing structural changes and luminescence properties of the treated materials.
• Fabricating and evaluating red-emitting lighting devices.

Main Results:

• Vitrified-devitrified MAS:Eu ceramics show enhanced red-emissions with near-unity luminescence efficiency.
• Materials exhibit improved thermal stability and longer persistent luminescence.
• Tunable blue-to-yellow emissions with red-afterglow were observed in original MAS:xEu powders.
• The process enables the creation of ultra-high brightness red-emitting lighting devices.

Conclusions:

• The vitrification-devitrification process significantly enhances luminescence in MAS:Eu materials.
• Oxygen-related defects and altered channel wall structure contribute to luminescence improvements.
• This approach offers a new pathway for designing high-performance luminescent materials for lighting.