Based on the coprecipitation and cation exchange method,narrow-band K2TiF6∶Mn4+ red phosphor was prepared by a HF-free liquid phase method.The effects of the ammonium fluoride and sulfuric acid (NH4F+H2SO4) reactant dosage and the doping concentration of Mn4+ on the morphology and luminescent properties of the samples were studied.A white light-emitting diode (WLED) was packaged using the synthesized K2TiF6∶Mn4+ with commercial Y3Al5O12∶Ce3+ and InGaN blue chips.The results showed that the prepared K2TiF6∶Mn4+ red phosphor had strong UV and blue absorption at ～360nm and ～465nm,and presented sharp emission peaks in the wavelength range of 600～650 nm.With the increase of the NH4F+H2SO4 dosage,the luminous intensity of the phosphor first increased and then decreased,and the sample showed concentration quenching effect when the doping concentration of Mn4+ was 10%.When the dosage of NH4F+H2SO4 was 60mmol and the doping concentration of Mn4+ was 8%,the optimal quantum efficiency of the prepared phosphor sample reached 67%,and the WLED device packaged with it achieved a color rendering index of 79.4 and a lumen efficiency of 80.62 lm/W.
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基金资助
国家自然科学基金青年基金项目(52002120);河南省博士后科研启动基金(202102075)
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