Preparation of Eu 3+-doped Ta 2O 5 phosphor particles by sol–gel method

Abstract

Eu 3+-doped Ta 2O 5 phosphor particles were prepared by a sol–gel method from tantalum (V) ethoxide (Ta(OC 2H 5) 5), surfactant sorbitantrioleate (SPAN85®), mixed solvent of C 2H 5OH and n-C 4H 9OH, and H 2O. Optical and structural properties of the particles were investigated by measuring luminescence and excitation spectra, luminescence quantum yield (QY), scanning electron microscope (SEM) images, and X-ray diffraction (XRD) patterns. The optimum conditions for preparing Eu 3+-doped Ta 2O 5 spherical phosphor particles were determined by changing pH value of sol solutions and the molar ratios of SPAN85/Ta(OC 2H 5) 5 and H 2O/Ta(OC 2H 5) 5. Under UV excitation, red luminescence mainly due to the 5D 0 → 7F J ( J = 1, 2, 4) transitions of Eu 3+ ions was observed. The strongest red luminescence with QY = 30% was obtained in 1Eu 2O 3-99Ta 2O 5 particles heat treated at 800 °C.