The development of an efficient blue phosphor with remarkable thermal stability required for high-quality white-light-emitting diodes (WLEDs) remains an exigent task and mainly concerned BaMgAl10O17:Eu2+ (BAM:Eu). Despite the outstanding performance of BAM:Eu, the reduction in luminescence efficiency under long-term operation results in numerous researches on new hosts having lattice rigidity with symmetrical coordination environment. Therefore, we have synthesized a competent blue-emitting Eu2+-activated Sr5SiO4Cl6 (SSC) phosphors. The admirable rigidity of these phosphors with three Sr polyhedra Sr(I)O9, Sr(II)O7, and Sr(III)O8 assessed from Rietveld refinement indicate the dense connectivity in the crystal structure, and the ab initio calculations further support the firm electronic band structure. The broad excitation from 250 to 450 nm suitably matches the absorption band of a near-UV (n-UV) LED chip. The phosphor exhibited bright blue emission with internal quantum yield and color purity > 90% which contribute to the slender fwhm of 33 nm. The first-principle calculation indicates the most stable site for Eu2+ substitution as Sr(III)O8, and the experimental results agreed with this fact as well. The synthesized phosphor displayed an excellent thermal stability which is superior to that of the commercial BAM:Eu phosphor. The excellent thermal stability may be owed to the highly symmetric coordination environment of Eu2+ in the SSC host that are revealed from the distortion and charge density distribution calculation by density functional theory. The blue phosphor was further utilized for WLEDs and displayed white light with a high color-rendering index and suitable correlated color temperature, which is ideal for practical applications in warm WLEDs.

中文翻译：

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Sr5SiO4Cl6：Eu2 +荧光粉的多位置占用驱动强烈窄带蓝色发射，具有出色的稳定性和色彩表现。

高质量白光发光二极管（WLED）所需的具有出色热稳定性的高效蓝色磷光体的开发仍然是紧迫的任务，并且主要涉及BaMgAl10O17：Eu2 +（BAM：Eu）。尽管BAM：Eu具有出色的性能，但是长期运行下发光效率的降低导致了对具有对称配位环境的具有晶格刚度的新型主体的大量研究。因此，我们合成了一种能发射蓝光的Eu2 +活化Sr5SiO4Cl6（SSC）荧光粉。通过Rietveld精制评估，这些磷光体具有三种Sr多面体Sr（I）O9，Sr（II）O7和Sr（III）O8，具有令人称赞的刚度，表明其晶体结构具有紧密的连通性，并且从头算计算进一步支持了该公司电子乐队结构。250至450 nm的宽激发适合与近紫外（n-UV）LED芯片的吸收带匹配。磷光体显示亮蓝色发射，内部量子产率和色纯度> 90％，这有助于实现33 nm的细长波长。第一性原理计算表明，最稳定的Eu2 +取代位点为Sr（III）O8，实验结果也与此事实相符。合成的荧光粉显示出优异的热稳定性，优于商业上的BAM：Eu荧光粉。优异的热稳定性可能归因于SSC主体中Eu2 +的高度对称配位环境，这是通过密度泛函理论从畸变和电荷密度分布计算得出的。