Warm white emission of Ca2P2O7: Dy3+, Eu3+ phosphor via hydrothermal method

Abstract

The Ca2P2O7: Dy3+, Eu3+ phosphors were synthesized via hydrothermal method. The three-dimensional network structure of Ca2P2O7 consisted of strong P-O covalent bond in [P2O7] and weak coupling between [P2O7] and Ca. The morphology was shown in detail by TEM and SEM images of precursors changed from spindles, tetragonal particles to long rods with the pH increased from 2 to 5. After sintering, the sample had the best luminescence property when pH was 4. The optimum sintering temperature was 1000 °C. The emission spectrum of Ca2P2O7: Dy3+ was composed of three emission peaks. Based on the optimized doping concentration of Dy3+ was 0.04 mol, the doping of Eu3+ ions increased the red emission of the samples and finally samples obtained warm white emitting. The concentration quenching mechanism in the energy transfer from Dy3+ to Eu3+ was caused by dipole-dipole interaction. Ca2P2O7: Dy3+, Eu3+ had excellent thermal stability. Thus, Ca2P2O7: Dy3+, Eu3+ phosphor which could emit warm white light has fantastic potential applications for UV excited LED.