Tunable light emission from single phased Ba2CaZn2Si6O17:Pb2+, Eu3+ silicate phosphors via energy transfer efficiency for white light emitting diode applications

In this work, the non-rare earth element Pb2+ ions doped, and co-doped with the rare earth element Eu3+ ions in the silicate based Ba2CaZn2Si6O17 phosphors were prepared by using the simple solid state reaction process. To know about the phase formation, and the surface morphology of the as prepared powder samples, the powder X-ray diffraction (PXRD), and the scanning electron microscope (SEM) techniques were employed respectively. To measure the luminescence properties of the phosphors, the photoluminescence excitation (PLE), and the photoluminescence (PL) emission were recorded. Under the 293 nm excitation, the co-doped phosphors (hereafter referred to as phosphors/samples) exhibit ‘a broad blue emission band at 438 nm’, and ‘five sharp bands at 579, 593, 611, 653, and 704 nm’, corresponding to the characteristic transitions of the Pb2+ and the Eu3+ ions in the same order. The energy transfer efficiency in the phosphors, between the sensitizer Pb2+, and the activator Eu3+ ions, was investigated. The effect of the concentration quenching is used to calculate the critical distance Rc in the sample was obtained to be 16.74 Å. The PL decay time showed a decreasing trend when the concentration of the Eu3+ activator ions was increasing. The PL emission spectra of the samples were used to measure the CIE chromaticity color coordinates, and the correlated color temperature (CCT). The quantum efficiency values of the samples were also measured. Finally, to know about the PL thermal stability of the phosphor, the temperature dependent photoluminescence (TDPL) was performed, and the activation energy was calculated as 0.167 eV. From the above results, the Ba2CaZn2Si6O17:Pb2+, Eu3+ phosphors can be the promising color tunable phosphors in the white light emitting diode (WLED) applications. [Display omitted] •The Pb2+/Eu3+ activated Ba2CaZn2Si6O17 phosphors were synthesized by solid state reaction method.•Ba2CaZn2Si6O17: Pb2+, Eu3+ phosphor exhibited good energy transfer efficiency.•The white light emitting phosphor Ba2Ca1-m-nZn2Si6O17: mPb2+ (m = 7 mol %), nEu3+ (n = 11 mol %) was obtained.•This phosphor showed a good thermal stability with the activation energy, 0.167 eV.