Combustion synthesis of Eu,Si‐doped AlN blue phosphor with varying Eu and Si concentrations

Abstract White light‐emitting diodes (LEDs) are favored for their efficiency and longevity. To enhance these properties, phosphors with high stability, such as nitrides and oxynitrides, are promising. Among these, AlN‐based blue phosphors co‐doped with Eu and Si offer high thermal and chemical stability, making them suitable for LEDs and displays. While high‐temperature synthesis methods are common, combustion synthesis provides a simpler alternative but requires optimization to control the reaction temperature, prevent unreacted material from remaining in the product, and enhance the luminescence efficiency. This study synthesizes Eu,Si‐doped AlN blue phosphors via combustion synthesis using Al, AlN, Eu 2 O 3 , Si 3 N 4 , and SrCO 3 as raw materials. The Eu and Si concentrations on luminescence properties are examined, along with the impact of Sr substitution at Eu sites to reduce the Eu content. The location of Eu in the synthesized phosphors is examined through atomic‐resolved scanning transmission electron microscopy. Photoluminescence and cathodoluminescence measurements reveal that optimized Eu and Si concentrations enhance luminescence through the formation of Si–Eu–O‐rich layers, while excessive Si induces yellowish emission due to the formation of Eu‐doped α‐Si₃N₄ or α‐SiAlON phases. Sr substitution increases luminescence intensity by reducing concentration quenching.