A Double Substitution of Mg2+鈥揝i4+/Ge4+ for Al(1)3+鈥揂l(2)3+ in Ce3+-Doped Garnet Phosphor for White LEDs

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• 作者：Mengmeng Shang ; Jian Fan ; Hongzhou Lian ; Yang Zhang ; Dongling Geng ; Jun Lin
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：July 21, 2014
• 年：2014
• 卷：53
• 期：14
• 页码：7748-7755
• 全文大小：573K
• ISSN：1520-510X

文摘

The influence of Mg²⁺鈥揝i⁴⁺/Ge⁴⁺ incorporation into Ce³⁺-doped Y₃Al₅O₁₂ garnet phosphors on the crystal structure and luminescence properties is described in this work. X-ray diffraction with Rietveld refinements, photoluminescence spectra, absolute quantum yield, thermal quenching behavior, and lifetimes were utilized to characterize samples. The introduction of Mg²⁺鈥揝i⁴⁺/Ge⁴⁺ leads to an obvious red shift of emission wavelength under the excitation of blue light, especially for the series of Mg²⁺鈥揝i⁴⁺ substitutions, which is suited for white light-emitting diodes (LEDs) with low color temperatures and good color rendering using only a single phosphor. More interestingly, an additional emission band locating at high-energy was observed with ultraviolet excitation, which is different than previous literature. Under the excitation of ultraviolet, the emission color for the Mg²⁺鈥揝i⁴⁺ substitutions can be tuned from yellow-green to blue, which is expected to obtain single-phased phosphors with white emission excited with UV-LED chip. The usual Ce³⁺ emission band at low energy has stronger quenching at high temperatures. The mechanisms for the observed phenomena are discussed.