Highly Stable Modified Phosphors of Ba2SiO4:Eu2+ by Forming a Robust Hydrophobic Inorganic Surface Layer of Silicon-Oxy-Imide-Carbide

A highly stable hydrophobic Ba2SiO4:Eu2+ (BSO) phosphor was produced by forming a robust hydrophobic inorganic silicon-oxy-imide-carbide layer on its surface. The process for developing this layer involved coating, ammonolysis, and pyrolysis of chlorosilane. The tightly adhered coating layer had a lotus, leaf-like micro- and nanohierarchical structure and contained CH3 groups, which enhanced the hydrophobicity of the modified phosphor significantly. The modified phosphors treated at 500 °C exhibited remarkable stability in their emission spectra, even after exposure to high-pressure water steam at 100 °C for 48 h, which is attributed to the high stability of the surface layer.