Luminescence characteristics of Dy3+ incorporated zinc borate powders

Abstract

We have synthesized powder samples of Dy3+ doped zinc borates by nitric acid method. X-ray diffraction (XRD) and environmental scanning electron microscope (ESEM) techniques were utilized to examine the structure and morphological observation of the samples. Luminescence characteristics of the samples were investigated using room temperature (RT) cathodoluminescence (CL) and radioluminescence (RL) measurements under excitation with electron beam and X-rays, respectively. The presence of small amounts of Dy3+ incorporated in the host lattice does not affect the structure of the prepared samples remarkably. The CL and RL spectra showed the characteristic emissions of Dy3+ (magnetic dipole transition of F-4(9/2) -> H-6(11/2) Blue; forced electric dipole transition of F-4(9/2) > H-6(13/2) Yellow; F-4(9/2) -> H-6(1/2) Red; F-4(9/2) -> (H-6(9/2) + H-6(11/2)) infrared). Thermoluminescence (TL) method was also conducted to determine the effects of various concentrations of Dy3+ on the TL properties of ZnB2O4. The TL glow peak of beta irradiated ZnB2O4:Dy3+ phosphors is a well-defined and centered at around 96 degrees C with a constant heating rate of 2 degrees C/s. Initial rise method was employed to observed main TL glow curve for determining the activation energy (E-a) and the frequency factor (s).