Red Photoluminescence from Bi3+ and the Influence of the Oxygen-Vacancy Perturbation in ScVO4: A Combined Experimental and Theoretical Study

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• 作者：Fengwen Kang ; Xiaobao Yang ; Mingying Peng ; Lothar Wondraczek ; Zhijun Ma ; Qinyuan Zhang ; Jianrong Qiu
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：April 10, 2014
• 年：2014
• 卷：118
• 期：14
• 页码：7515-7522
• 全文大小：582K
• 年卷期：v.118,no.14(April 10, 2014)
• ISSN：1932-7455

文摘

We report on a red-emitting ScVO₄:Bi³⁺ phosphor which does not show excitation at energies below 2.88 eV (430 nm). X-ray diffraction, time-resolved, and quantitative photoluminescence (PL) spectroscopy were employed to characterize relations between crystal structure and luminescence properties of the material. Results show that incorporation of Bi³⁺ renders the blue photoemission of blank ScVO₄ to red. Dynamic luminescence analysis between 10 and 300 K reveals a complicated dependence of energy transfer from VO₄^{3鈥?/sup> groups to Bi3+ ions and population redistribution of 3P₁ and 3P₀ of Bi3+ on temperature. This reflects in distinct changes in the luminescence decay functions. That is, a dramatic decrease of Bi3+ luminescence lifetime occurs from hundreds to only several microseconds. Density functional theory is employed to reveal how the unusual red Bi3+ luminescence comes, and results indicate that the perturbation of oxygen vacancies which is generated readily when bismuth precipitates into ScVO₄ is the reason for the experimental observation, although the vacancies themselves do not show photoluminescence. Upon excitations at 330 and 380 nm, internal quantum efficiencies can be up to 56% and 47%, respectively, implying the potential application of the red phosphor in warm-white-light-emitting diodes. As a proof of concept, an exemplary device was developed by combining the present phosphor with an ultraviolet-light-emitting diode and a commercial phosphor (Ba, Eu)MgAl₁₀O₁₇:Mn. We obtain a color rendering index (CRI) of >90 and a color temperature of 4306 K at chromaticity (0.3744, 0.3991).}