Research progress on surface modifications for phosphors used in light-emitting diodes (LEDs)

Area of Science:

• Materials Science
• Solid-State Lighting
• Optoelectronics

Background:

• Phosphors are crucial for efficient solid-state lighting in light-emitting diodes (LEDs).
• Common phosphors face challenges including low photoluminescence (PL) efficiency, poor stability, and thermal degradation, hindering LED performance.
• Addressing these limitations is vital for advancing LED technology.

Purpose of the Study:

• To review surface modification techniques for various phosphors used in LED lighting.
• To explain the mechanisms behind improved phosphor stability, PL efficiency, and reduced thermal degradation.
• To explore advanced methods like embedding phosphors in inorganic glass matrices.

Main Methods:

• Reviewing surface modification strategies for fluoride, sulphide, silicate, oxide, nitride, and oxynitride phosphors.
• Analyzing protective layer formation, inorganic/organic coating, and surface passivation techniques.
• Investigating phosphor embedding in inorganic glass matrices, particularly for quantum dots.

Main Results:

• Surface modification effectively enhances phosphor stability against moisture and heat (fluoride/sulphide phosphors).
• Coating improves PL efficiency in silicate and oxide phosphors.
• Passivation reduces thermal degradation in nitride and oxynitride phosphors.
• Inorganic glass embedding offers a viable route to boost phosphor stability.

Conclusions:

• Surface modification is a key strategy to overcome limitations in LED phosphors.
• Tailored surface treatments significantly improve phosphor performance and durability.
• Future research should focus on developing novel surface modification and embedding techniques for next-generation LEDs.