Structural and luminescence study of Ce3+ and Eu3+ doped ZnAl12O19 nano-structured novel phosphors

Abstract

Cerium and Europium ions activated ZnAl12O19 nano-phosphors were first time prepared by solution combustion synthesis. The prepared powder samples were characterized by X-Ray Diffraction (XRD), High-resolution transmission electron microscopy (HR-TEM), Ultraviolet visible spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FT-IR) and Photoluminescence technique (PL). The crystal structure of the prepared ZnAl12O19 host, and Ce3+ and Eu3+ doped ZnAl12O19 phosphors were calculated by XRD technique. The nano-structured nature of the prepared samples was confirmed by the HR-TEM technique. The band gap energies of prepared undoped, and Ce3+ / Eu3+ doped ZnAl12O19 nano-phosphor were calculated using the UV spectroscopy technique. The bonding nature in the prepared samples was studied by the FT-IR technique. Under 320 nm excitation wavelength, the PL emission spectrum of Ce3+ activated ZnAl12O19 nano-phosphor shows broad emission centered at 420 nm, which is ascribed due to the transitions of the 5d excited state to its ground-state configurations of the 2F7/2 of the Ce3+ ions. Furthermore, under 390 nm excitation the PL emission spectra of Eu3+ activated ZnAl12O19 nano-phosphor shows sharp emission peak at 590 nm corresponding to the 5D0→7F1 transition of Eu3+ ions. The CIE chromaticity coordinates for the optimum nano-phosphor were found to be (0.1573, 0.0693) and (0.5717, 0.4276) for Ce3+ / Eu3+ doped ZnAl12O19 phosphors, respectively. Therefore these synthesized phosphors may be applicable in display devices and solid state lighting applications.