β-Sialon:Eu²⁺ has been reported to be the most promising narrow-band green phosphor for wide color gamut LCD backlights, but the coexistence of the Eu³⁺ luminescence killer with the Eu²⁺ luminescence center limits its luminescence performance to a great extent. In this study, we propose a direct reduction strategy to successfully realize the reduction of Eu³⁺ to Eu²⁺ and, finally, increase the effective concentration of Eu²⁺ in the crystal lattice and greatly minimize the amount of Eu³⁺ on the particle surface. As a result, the luminescence of treated β-sialon:Eu²⁺ is enhanced by 2.3 times, and the internal quantum efficiency significantly increases from 52.2 to 96.5%. The mechanisms for such large enhancements in luminescence are clarified by investigating the microstructure, luminescence spectra, valence state, concentration, and distribution of Eu using a variety of chemical analyses. We find that the low efficiency is ascribed to the coexistence of the Eu³⁺ luminescence killer with the Eu²⁺ luminescence center. The white LED backlight using the treated β-sialon:Eu²⁺ demonstrates a high luminous efficacy of 136 lm W^–1 (22.5% up) and a wide color gamut (∼96% National Television System Committee standard (NTSC)), which thus promises high brightness and energy saving. We believe that the strategy proposed in this work would also work for other luminescent materials containing mixed valence of dopants.

中文翻译：

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通过减少Eu ³⁺发光杀灭剂，实现高量子效率的窄带β-Sialon：Eu ²⁺荧光粉用于高亮度LCD背光灯

据报道，β-Sialon：Eu ²⁺是用于宽色域LCD背光的最有前途的窄带绿色磷光体，但是Eu ³⁺发光杀手和Eu ²⁺发光中心的共存将其发光性能限制为很大程度上。在这项研究中，我们提出了一种直接还原策略，以成功实现将Eu ³⁺还原为Eu ²⁺，最后增加晶格中Eu ²⁺的有效浓度，并最大程度地减少了Eu ³⁺在晶格中的含量。粒子表面。结果，处理过的β-赛隆：Eu ²⁺的发光量子效率提高了2.3倍，内部量子效率从52.2显着提高到96.5％。通过使用各种化学分析方法研究Eu的微观结构，发光光谱，价态，浓度和分布，从而阐明了这种大幅度增强发光的机理。我们发现低效率归因于Eu ³⁺发光杀手与Eu ²⁺发光中心的共存。使用经过处理的β-sialon：Eu ²⁺的白色LED背光灯显示出136 lm W ^–1的高发光效率（高达22.5％）和较宽的色域（约96％的国家电视系统委员会标准（NTSC）），因此具有较高的亮度和节能效果。我们认为，这项工作中提出的策略也将适用于其他含有混合价掺杂物的发光材料。