Abstract A series of efficient red phosphors, K2SiF6:Mn4+ (KSFM) particles with highly regular, uniform and anisotropic shapes, were successfully prepared by a two-step chemical co-precipitation method at room temperature without using surfactant and template. A morphological map for KSFM particles with five distinctive shapes was depicted by adjusting KF-HF precipitator dropping speed. Moreover, the photoluminescence, decay curves and Raman spectral dependence of the KSFM phosphors with different morphologies were investigated. Luminescence intensity of the KSFM phosphors is highly correlated with the morphology of KSFM particles, which gradually increased as the particle shapes changed from cube to octahedron. Whereas, Raman spectra and flame atomic absorption spectrophotometer results indicated that Mn4+ concentration in a series of KSFM particles decreased gradually. Growth mechanism of particle is discussed base on reticular density and surface energy. White LED devices made of a blue GaN chip merged with yellow phosphor (YAG: Ce3+) and the obtained KSFM red phosphor could produce warm white light. Drive current testing of the fabricated w-LEDs proved the KSFM phosphor in octahedron shape is more stable than that of the KSFM in cubic shape.

中文翻译：

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红色荧光粉 K2SiF6:Mn4+：可控合成、生长机制和形状相关的发光特性

摘要 在不使用表面活性剂和模板剂的情况下，在室温下通过两步化学共沉淀法成功制备了一系列具有高度规则、均匀和各向异性形状的高效红色荧光粉K2SiF6:Mn4+ (KSFM)颗粒。通过调整 KF-HF 除尘器下落速度，描绘了具有五种不同形状的 KSFM 颗粒的形态图。此外，研究了具有不同形态的 KSFM 荧光粉的光致发光、衰减曲线和拉曼光谱依赖性。KSFM 荧光粉的发光强度与 KSFM 颗粒的形态高度相关，随着颗粒形状从立方体变为八面体，其逐渐增加。然而，拉曼光谱和火焰原子吸收分光光度计结果表明，一系列KSFM颗粒中的Mn4+浓度逐渐降低。基于网状密度和表面能讨论了粒子的生长机制。由蓝色GaN芯片与黄色荧光粉（YAG：Ce3+）混合制成的白色LED器件，得到的KSFM红色荧光粉可以产生暖白光。制造的 w-LED 的驱动电流测试证明八面体形状的 KSFM 荧光粉比立方体形状的 KSFM 荧光粉更稳定。