Enhanced luminescence properties and Judd-Ofelt analysis of novel red emitting Sr2LiScB4O10: Eu3+ phosphors for WLED applications

Abstract

In this work, a new series of red emitting Eu 3+ ions activated Sr 2 LiScB 4 O 10 phosphors were synthesized by a traditional high temperature solid-state reaction technique and their structural and luminescence behavior were studied through analyzing X-ray diffraction, Scanning electron microscopy, Fourier transform infrared spectroscopy, optical absorption, photoluminescence as well as decay spectral measurements, respectively. XRD pattern showed that the prepared Sr 2 LiScB 4 O 10 :Eu 3+ phosphors crystallized into monoclinic system with the space group of P2 1 /n. FTIR study revealed the presence of different stretching and bending vibrational bands of borate group. Bonding parameter values which obtained from the band positions of the absorption spectra revealed the covalent character which existing between the Eu 3+ ions and its surrounding ligands. Under 395 nm excitation source, the studied phosphors exhibit intense red emissions in the 617 nm wavelength region corresponding to the 5 D 0 → 7 F 2 transition of Eu 3+ ions. Judd-Ofelt (JO) intensity parameters were evaluated from the PL emission spectra in order to facilitate a study of the nature of site symmetry. From the CIE color chromaticity analysis it is evident that the prepared phosphors are found to emit an intense red light with the reasonable color coordinate and color purity under the excitation of blue light and the same may be suggested as an appropriate red component for developing white LEDs. The important radiative parameters were obtained for the emission transitions using JO intensity parameters in order to ensure the suitability of prepared phosphors for display devices and laser applications. • Eu 3+ : Sr 2 LiScB 4 O 10 phosphors were fabricated by solid state reaction method for display device applications. • Eu 3+ activated Sr 2 LiScB 4 O 10 phosphors exhibited red luminescence which was confirmed by CIE chromaticity diagram. • Higher and increasing Ω 2 values contribute to the higher degree of covalency between Eu–O bond. • Bright red light with color purity of 94% was attained in the prepared phosphors excited by 395 nm. • 0.6EuSLSB phosphor exhibit appreciable radiative properties suitable for red laser and white LEDs.