Structure, luminescence, properties and energy transfer of Dy3+ and Eu3+ codoped Ca4LaO(BO3)3 phosphor

Abstract

A novel white light emitting phosphor with adjustable color Ca4LaO(BO3)3:Dy3+,Eu3+ was synthesized by high temperature solid phase method. The crystal structure, luminescence characteristics, fluorescence lifetime and energy transfer were studied by X-ray diffractometer and fluorescence spectrometer. It was found that Ca4LaO(BO3)3:Dy3+ had the best emission under the excitation wavelength of 348 nm. Under 348 nm excitation, the emission peaks are located at 491 nm, 587 nm and 613 nm, respectively. Emission spectrum and fluorescence lifetime analysis showed that, by increasing Eu3+ concentration, the strength and lifetime of Dy3+ decrease continuously, and the increasing of the emission intensities of Eu3+ indicated that energy transfer existed in Ca4LaO(BO3)3:Dy3+,Eu3+. after calculation, it was found that the main mode of energy transfer in the phosphor was dipole-dipole interaction. According to the color coordinate and formula, by increasing the concentration of Eu3+, the color temperature of Ca4LaO(BO3)3:Dy3+,Eu3+ decreased continuously, and the color shifted from cold white light to warm white light and finally moved towards red light. This phenomenon is of great help to the lack of warm white light in the LED market. Therefore, Ca4LaO(BO3)3:Dy3+,Eu3+ have good market application prospects.