On Doping Eu3+ in Sr0.99La1.01Zn0.99O3.495: The Photoluminescence, Population Pathway, De-Excitation Mechanism, and Decay Dynamics

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• 作者：Rui Shi ; Biquan Li ; Chunmeng Liu ; Hongbin Liang
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：September 1, 2016
• 年：2016
• 卷：120
• 期：34
• 页码：19365-19374
• 全文大小：722K
• 年卷期：0
• ISSN：1932-7455

文摘

Eu³⁺, with the 4f⁶ electronic configuration, generally exhibits bright red f-f emissions arising from its ⁵D₀ multiplet, and Eu³⁺ doped phosphors have attracted lots of attention for applications in lighting and display fields. However, the electron population mechanisms between relevant Eu³⁺ excited states as well as charge-transfer state (CTS) still need to be further clarified since the puzzles on these issues limit the exploration of new luminescent materials and the improvement of the luminescence efficiency of the potential phosphors. In this work, a series of Sr_0.99[La_(1–x)Eu_x]_1.01Zn_0.99O_3.495 phosphors was prepared by a high-temperature solid-state reaction technique and was characterized by X-ray diffraction (XRD) measurements at different temperatures, infrared (IR) spectrum, and diffusion reflectance spectra (DRS) at room temperature (RT). The temperature-, doping concentration-, and excitation wavelength-dependent luminescence properties were systematically studied to clarify the population pathway, de-excitation mechanism, and decay dynamics of Eu³⁺ in this low-phonon-frequency compound. The impacts of cross relaxation (CR) and multiphonon relaxation (MPR) processes on the luminescence and decay spectra were investigated in detail. The special coordination polyhedron around Eu³⁺ played a dominant role in the intense Eu^3+ 5D₀–⁷F₄ emission. The CTS peaks shifted to longer wavelengths with increasing temperatures, which seems to relate to the lattice expansion at higher temperatures.