Mixed-Phase Engineering in Single Particles for Enhancing Performance of Fe³⁺ Doped Mg₃Ga₂GeO₈ Phosphors

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Chemistry

Background:

• High-efficiency and broadband near-infrared (NIR) phosphors are crucial for advanced optoelectronics.
• Simultaneously improving quantum efficiency and thermal stability in NIR phosphors remains a significant challenge.

Purpose of the Study:

• To develop a novel phosphor with enhanced NIR luminescence and thermal stability.
• To investigate the effect of Al3+ substitution on the structure and properties of Mg3Ga2GeO8:Fe3+ phosphors.

Main Methods:

• Synthesized Mg3Ga2GeO8:Fe3+ phosphors with varying concentrations of Al3+ substituting Ga3+.
• Characterized the structural, optical, and thermal properties of the synthesized phosphors.
• Fabricated a near-ultraviolet chip-based NIR phosphor-converted light-emitting diode (pc-LED) device.

Main Results:

• Al3+ substitution induced a structural transformation from single-phase to single-particle multiphase structure.
• The optimized phosphor achieved a high quantum yield of 92.6% and excellent thermal stability (89.4% at 150 °C).
• The fabricated pc-LED demonstrated a stable NIR output power of 1.97 mW at 120 mA.

Conclusions:

• Inducing a single-particle multiphase structure via ion substitution is an effective strategy for optimizing Fe3+-doped phosphors.
• The developed multiphase phosphor shows great potential for applications in night vision imaging and noninvasive blood vessel visualization.
• This work provides valuable insights for designing high-performance NIR phosphors.