Facile hydrothermal synthesis and pulsed laser deposition of Ca 0.5 Y 1−x (WO 4 ) 2 :xEu 3+ phosphors: investigations on the luminescence, Judd–Ofelt analysis and charge compensation mechanism

Herein, we present the rare-earth (RE) activated Ca 0.5 Y 1−x (WO 4 ) 2 : x Eu 3+ phosphors prepared using a surfactant-assisted hydrothermal route. From the synthesized powder samples of Ca 0.5 Y 1−x (WO 4 ) 2 : x Eu 3+ , nanosized, thin phosphor films were fabricated based on the pulsed laser deposition (PLD). Structural studies suggest that Ca 0.5 Y 1−x (WO 4 ) 2 doped with Eu 3+ belongs to the scheelite tetragonal crystal structure. The powder phosphors show signs of bi-pyramid-like micro-architectures. The down-conversion luminescence studies suggest the presence of a predominant transition attributed to the red color in the visible region. The Judd–Ofelt theory has been incorporated to estimate the photophysical parameters and luminescence quantum efficiencies of both Ca 0.5 Y 1−x (WO 4 ) 2 : x Eu 3+ powder and thin film phosphors. The color chromaticity coordinates and luminescence decay times were estimated. The effect of alkali compounds on the prepared powder phosphors was investigated. The results indicate that both the powder and thin film phosphors are the best candidates for display and electro/cathodo-luminescence applications.