Optimized luminescent intensity of Ca2MgWO6:Er3+,Yb3+ up-conversion phosphors by uniform design and response surface methodology

Abstract

In this work, an experimental optimization design methodology was used to determine the accurate optimal doping concentrations of a specific multi-doped luminescent material with the strongest expected luminescent intensity. Taking Ca2MgWO6:Er3+,Yb3+ up-conversion phosphors as an example, the global optimization of Er3+ and Yb3+ doping concentrations was carried out through a two-step optimization method combining uniform design and response surface methodology. 5-Level-2-factor central composite design was applied to optimize the levels of factors. Impressively, the significance level of established regression model was fully assessed by analysis of variance and its confidence can reach 95%. In addition, genetic algorithm was exploited to solve this regression equation and the optimal doping concentrations of Er3+ and Yb3+ were successfully determined to be 4.682 mol% and 13.556 mol%, respectively. The optimal sample designed by simulation calculation and the sample obtained by variable-controlling method were elaborated. And their luminescent performances and structures were fully investigated. Compared with the traditional sample, the luminescent intensity of the designed optimal sample is enhanced by 1.34 times, featuring an intensity of 2,184,879 that is very close to the desired theoretical value 2,106,800. All of the results suggest that such an experimental optimization strategy could be a new route to optimize luminescent properties of multi-doped phosphors.