Journal of Applied Chemical Science International

Color tunable, highly intense, long persistent M₂MgSi₂O₇ (M=Ca, Sr, Ba) phosphors were prepared by one pot hydrothermal method. The phosphor particles were well controlled by the solution pH of the mixture that tuned the luminescence intensities significantly. Compared with the conventional solid state method, narrow particles size distribution, homogeneous and agglomeration free particles were achieved by hydrothermal method. The underlined mechanism of particles formation in regard to the pH of the starting mixture was proposed. Fine tuning of fluorescence and afterglow color was achieved by changing host cations. Bluish green, green and yellowish-green afterglow were observed in the Sr₂MgSi₂O₇:Eu²⁺,Dy³⁺, Ba₂MgSi₂O₇:Eu²⁺,Dy³⁺ and Ca₂MgSi₂O₇:Eu²⁺,Dy³⁺ phosphors, respectively. The afterglow duration was found to be in the order Ca₂MgSi₂O₇ > Ba₂MgSi₂O₇ > Sr₂MgSi₂O₇ and was discussed in term of the trap depths in the respective hosts. Optimum Eu²⁺ activator and Dy³⁺ trapping centers were estimated for intense afterglow with longer persistent duration. These yellowish-green afterglow phosphors which are difficult to realize might have potential applications due to superior water resistant properties.