Synthesis of Eu³⁺-Doped NaGd₉Si₆O₂₆ Sub-Microcrystals from a NaGdF₄@SiO₂ Structure

Area of Science:

• Materials Science
• Solid-state Chemistry
• Luminescence

Background:

• Rare earth silicate phosphors are crucial for high-efficiency displays and illumination due to their stable performance.
• Conventional solid-state synthesis yields large grains, limiting color purity and light extraction in high-resolution LEDs.
• Controlling phosphor particle size is key to optimizing performance in optoelectronic devices.

Purpose of the Study:

• To develop a novel synthetic route for producing sub-microcrystal rare earth silicate NaGd9Si6O26 (NGSO).
• To investigate the reaction mechanism and optical properties of the synthesized NGSO sub-microcrystals.
• To evaluate the performance enhancement of LEDs utilizing these sub-microcrystals compared to conventionally synthesized materials.

Main Methods:

• Fabrication of NGSO sub-microcrystals via a designed synthetic route.
• Characterization of sub-microcrystal size distribution (550-1200 nm).
• Systematic investigation of reaction mechanisms and optical properties, including quantum efficiency measurements.
• Performance testing of LEDs encapsulated with synthesized sub-microcrystals versus conventional NGSO.

Main Results:

• Successfully synthesized NaGd9Si6O26 (NGSO) sub-microcrystals with controlled sizes.
• Achieved a quantum efficiency of approximately 36.6% for Eu3+-activated NGSO sub-microcrystals.
• LEDs using sub-microcrystal NGSO exhibited reduced color deviation.
• Demonstrated higher lumen efficiency and lumen flux in LEDs incorporating the sub-microcrystal phosphors.

Conclusions:

• The designed synthetic route effectively produces sub-microcrystal NGSO phosphors with desirable optical properties.
• Sub-microcrystal NGSO phosphors significantly improve LED performance metrics like color accuracy and luminous efficacy.
• This advancement offers a pathway for developing next-generation high-resolution display and illumination technologies.