Efficient red-luminescence of CaLa2ZnO5 phosphors co-doped by Ce3+and Eu3+ ions

초록

Individually and doubly doped Ce3+/Eu3+:CaLa2ZnO5 (CLZO) phosphors were synthesized by a conventional sol-gel method as highly efficient luminescence-based phosphor materials. X-ray diffraction and field-emission scanning electron microscope were used to analyze the structural and morphological properties. The elements and their ionic states were determined by energy-dispersive spectroscopy and X-ray photoelectron spectroscopy studies, respectively. The assignment of the functional groups was analyzed using Fourier-transform infrared spectral studies. Bright red emission was obtained from Eu3+-doped CLZO phosphors due to its hypersensitive transition of D-5(0)-> F-7(2) at 626 nm with a royal blue excitation source. By increasing the Eu3+ content, the emission features were rapidly enhanced. Moreover, the red emission related to Eu3+ was further increased by the addition Ce3+ ions as a co-dopant along with Eu3+ in the CLZO matrix due to energy transfer. The energy migration from Ce3+ to Eu3+ is systematically illustrated by several fluorescent approaches, such as photoluminescence analysis, spectral overlap, CIE coordinates, lifetime dynamics, luminescence quantum yields, and color purity. Surprisingly, the CIE coordinates were very close to the NTSC coordinate values. Based on the results, these phosphors could be suitable materials for luminescence-based optoelectronic devices. (C) 2019 Elsevier B.V. All rights reserved.

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