Journal ArticleDOI
Narrow Red Emission Band Fluoride Phosphor KNaSiF6:Mn4+ for Warm White Light-Emitting Diodes
Ye Jin,Mu-Huai Fang,Marek Grinberg,Sebastian Mahlik,Tadeusz Lesniewski,Mikhail G. Brik,Mikhail G. Brik,Mikhail G. Brik,Guan-Yu Luo,Jauyn Grace Lin,Ru-Shi Liu +10 more
TLDR
Results reveal that KNaSiF6:Mn(4+) presents good luminescent properties and could be a potential candidate material for application in back-lighting systems.Abstract:
Red phosphors AMF6:Mn4+ (A = Na, K, Cs, Ba, Rb; M = Si, Ti, Ge) have been widely studied due to the narrow red emission bands around 630 nm. The different emission of the zero-phonon line (ZPL) may affect the color rendering index of white light-emitting diodes (WLED). The primary reason behind the emergence and intensity of ZPL, taking KNaSiF6:Mn4+ as an example, was investigated here. The effects of pressure on crystal structure and luminescence were determined experimentally and theoretically. The increase of band gap, red shift of emission spectrum and blue shift of excitation spectrum were observed with higher applied pressure. The angles of ∠FMnF and ∠FMF(M = Si, Ti, Ge) were found clearly distorted from 180° in MF62– octahedron with strong ZPL intensity. The larger distorted SiF62– octahedron, the stronger ZPL intensity. This research provides a new perspective to address the ZPL intensity problem of the hexafluorosilicate phosphors caused by crystal distortion and pressure-dependence of the lumine...read more
Citations
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Journal ArticleDOI
Mn2+ and Mn4+ red phosphors: synthesis, luminescence and applications in WLEDs. A review
Qiang Zhou,Leonid Dolgov,Alok Mani Srivastava,Lei Zhou,Zhengliang Wang,Jianxin Shi,Miroslav D. Dramićanin,Mikhail G. Brik,Mikhail G. Brik,Mikhail G. Brik,Mingmei Wu,Mingmei Wu +11 more
TL;DR: An overview of recent studies on transition metal activated phosphors can be found in this article, including detailed synthesis routes (solid-state reaction and wet-chemical synthesis) and description of luminescence mechanisms and phosphors' behaviors; discuss their promising applications in white light-emitting diodes.
Journal Article
On the absorption spectra of complex ions. II
Yukito Tanabe,Satoru Sugano +1 more
TL;DR: In this paper, the authors solved the energy levels which are important in the absorption spectra of the normal complex ions, leaving the crystalline field strength as a parameter, and calculated positions of lines and bands are rather in good agreement with the experimental data in divalent ions [MX 6 ] 2+ (M=Cr, Mn, Fe, Co, Ni), when they adjust the crystallINE field parameter D q suitably.
Journal ArticleDOI
Quenching of the red Mn4+ luminescence in Mn4+-doped fluoride LED phosphors
TL;DR: Detailed insights into temperature and concentration quenching of Mn4+ emission are provided and can be used to realize superior narrow-band red Mn4-doped fluorides for w-LEDs and improve the efficiency of white LEDs by considering the thermal properties of their coatings.
Journal ArticleDOI
Highly Efficient and Thermally Stable K3AlF6:Mn4+ as a Red Phosphor for Ultra-High-Performance Warm White Light-Emitting Diodes.
Enhai Song,Jianqing Wang,Jiahao Shi,Tingting Deng,Shi Ye,Mingying Peng,Jing Wang,Lothar Wondraczek,Qinyuan Zhang +8 more
TL;DR: It is found that the Mn4+ ions at the distorted octahedral sites in K3AlF6:Mn4+ can produce a high photoluminescence thermal and color stability, and higher quantum efficiency (QE) that are in turn responsible for the realization of a high LE by the warm W-LEDs.
Journal ArticleDOI
Highly Efficient and Stable Narrow-Band Red Phosphor Cs2SiF6:Mn4+ for High-Power Warm White LED Applications
Enhai Song,Yayun Zhou,Xiao-Bao Yang,Zifeng Liao,Weiren Zhao,Tingting Deng,Wang Lingyan,Y. Y. Ma,Shi Ye,Qinyuan Zhang +9 more
TL;DR: In this paper, a thermally stable red fluoride phosphor, Cs2SiF6:Mn4+, with a high internal quantum efficiency (IQE) of 89% and ultrahigh EQE of 71% is demonstrated.
References
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