Jia Yajun, Pan Yuexiao, Zhu Jiawen, Chen Xi'an, Wang Aiyin, Lian Hongzhou, Lin Jun
Key Laboratory of Carbon Materials of Zhejiang Province, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, P.R. China.
Dalton Trans. 2020 Oct 6;49(38):13226-13232. doi: 10.1039/d0dt02521f.
Red emitting phosphors of Mn4+ doped fluorides are in high demand because the high color purities of phosphors make them potentially useful white light-emitting diodes (WLEDs) as backlights of electronic devices. We herein report an efficient red emitting phosphor KRbGeF6 : Mn4+ (KRGF : Mn) that was prepared by an in situ one-pot ion-exchange method at room temperature without organic solvents or HF. Homogenous mixtures of the starting materials with a stoichiometric KRGF : Mn ratio were partly dissolved in various acid solutions, and [MnF6]2- and [GeF6]2- successively underwent ion exchange under stirring. More importantly, in situ recrystallization of KRGF : Mn occurred simultaneously in solution with water as a solvent. Evidently, the formation of stable KRGF : Mn crystals propels the processes of dissolution and ion exchange. We also investigated the effect of inorganic acids on the resultant phases and photoluminescence properties of KRGF : Mn. The red phosphor KRGF : Mn prepared in HCl solution shows the highest luminescence intensity with an yield of 80%.
