Luminescence of Sm-doped CaMoO_4 phosphors prepared by sol-gel process

摘要

This work studies the effect of calcination temperature on the photoluminescene property of the Sm-doped CoMoO_4 to develop new white phosphors for the application in white light emitting diodes (LEDs) by controlling preparation temperature. The Sm-doped CaMoO_4 (5 at% Sm~(3+)) phosphors were fabricated by the sol-gel process. Experiment results indicated that the matrices of the phosphors and Sm cation in the phosphors show blue-green and red emissions, respectively, and their intensities changed inversely with the calcination temperature. The CIE chromaticity coordinate calculation further revealed that the visible luminescence of the phosphors obviously changes with calcination temperature, and the phosphors synthesised at calcination temperature of 600℃ show white emission. The luminescence variation of the phosphors with calcination temperature was discussed on the basis of microstructural characterisations of the phosphors.