Luminescence properties of Ce³⁺ and Tb³⁺ co-activated ZnAl₂O₄ phosphor

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• 作者：K.G. Tshabalala^a ; S.-H. Cho^b ; J.-K. Park^b ; Shreyas S. Pitale^a ; I.M. Nagpure^a ; R.E. Kroon^a ; H.C. Swart^a ; O.M. Ntwaeaborwa^a ; ^{ntwaeab@ufs.ac.za}
• 关键词：Combustion synthesis ; Phosphor ; Emission ; Cathodoluminescence
• 刊名：Physica B
• 出版年：2012
• 期刊代码：53_09214526
• 类别：ph
• 出版时间：15 May, 2012
• 卷：407
• 期：10
• 页码：1489-1492
• 文件大小：713 K

摘要

In this study, a solution combustion method was used to prepare green emitting Ce³⁺-Tb³⁺ co-activated ZnAl₂O₄ phosphor. The samples were annealed at 700 掳C in air or hydrogen atmosphere to improve their crystallinity and optical properties. X-ray diffraction study confirmed that both as-prepared and post-preparation annealed samples crystallized in the well known cubic spinel structure of ZnAl₂O₄. An agglomeration of irregular platelet-like particles whose surfaces were encrusted with smaller spheroidal particles was confirmed by scanning electron microscopy (SEM). The fluorescence data collected from the annealed samples with different concentrations of Ce³⁺ and Tb³⁺ show the enhanced green emission at 543 nm associated with ⁵D₄鈫?sup>7F₅ transitions of Tb³⁺. The enhancement was attributed to energy transfer from Ce³⁺ to Tb³⁺. Possible mechanism of energy transfer via a down conversion process is discussed. Furthermore, cathodoluminescence (CL) intensity degradation of this phosphor was also investigated and the degradation data suggest that the material was chemically stable and the CL intensity was also stable after 10 h of irradiation by a beam of high energy electrons.