Red emitting phosphor K2SiF6:Mn4+: Controlled synthesis, growth mechanism, and shape-dependent luminescence properties

• Published in: Journal of luminescence 2020-10, Vol.226, p.117426, Article 117426
• Main Authors: Qiu, Shijie, Wei, Hengwei, Wang, Xiaoming, Zhang, Shuai, Wang, Mengmeng, Wang, Yiying, Xu, Ling, Jiao, Huan
• Format: Article
• Language: English
• Subjects: Evolving morphology; K2SiF6: Mn4+ phosphor; Red emission; White LED
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2020.117426

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. [Display omitted] 1)A series of K2SiF6:Mn4+ (KSFM) particles were prepared by solid state method.2)The morphology of KSFM particles is highly regular, uniform and anisotropic.3)Photoluminescence and decay curves of the KSFM phosphors are investigated.4)Raman spectra dependence of the KSFM phosphors is discussed.5)Growth mechanism of particle is based on reticular density and surface energy.