Sol–Gel Synthesis of an Efficient Blue CaMgSi2O6 : Eu2 + Thin-Film Phosphor with Two-Dimensional Triangular-Lattice SiNx Air-Hole Photonic Crystal

Abstract

thin-film phosphors (TFPs) were grown on sapphire substrates using a simple Pechini-type sol–gel (PSG) deposition technique. After deposition, the 10-layer-coated films ( thick) were then annealed between 900 and for 2 h in a gas flow. The optical properties, morphology, and crystallographic structures of the TFPs were characterized. The PSG process produced efficient TFPs with a pure blue color (, ), a high crystallinity, and a smooth morphology. To enhance photoluminescence (PL) emission, two-dimensional (2D) triangular-lattice air-hole photonic crystal layers (PCLs) were introduced into the TFPs using nanosphere lithography. The normally directed PL intensity of the PSG-derived TFP with a 2D triangular-lattice air-hole PCL was 11.4 times higher than that of a flat TFP. The enhanced PL efficiency of the PSG-derived TFPs was attributed to the combined increase in the extraction of blue emission light and the absorption of UV excitation light through Bragg scattering and the leaky modes produced by the 2D PCLs.