Sol-gel method and optical properties of Ca12Al14O32F2：Eu3＋ red phosphors

Ca12Al14O32F2:Eu3+ red phosphors were prepared by the sol-gel method with CF3 COOH as the fluorine source. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectra, and photoluminescence spectra, as well as thermogravimetric and differential thermal analysis were utilized to characterize the samples. All the samples were single phase with a cubic structure. The as-obtained Ca12Al14O32F2:Eu3+ red phosphors consisted of nanoparticles with sizes of approximately 40–100 nm. Under the excitation of UV light, Ca12Al14O32F2:Eu3+ exhibited the characteristic emissions of Eu3+, and the effect of annealing temperature, annealing time, and CF3 COOH and Eu3+ concentrations on the luminescence intensity were discussed in detail.