Concentration effects of fluorescence quenching and optical transition properties of Dy3+ doped NaYF4 phosphor

Doping concentration is an important factor influencing the optical and spectroscopic properties of rare earth doped luminescence materials. In this work, the influences of Dy3+ concentration on fluorescence intensity and optical transition properties were studied. Huang's and Uitert's models were compared and used in discovering the fluorescence intensity quenching mechanism of Dy3+ in NaYF4 phosphors, and it was found that from these two models the fluorescence intensity quenching mechanism can be well deduced though the application manners of the models are different. The dependence of optical transition properties on Dy3+ doping concentration was studied in depth. It was found that with increasing Dy3+ concentration the Ω2 value increases and the Ω4 value decreases monotonically, nevertheless the Ω6 value changes slightly. Moreover, the magnitude sequence of the Judd-Ofelt parameters changes from Ω4>Ω6>Ω2 to Ω2>Ω6>Ω4 when the concentrations of Dy3+ increases. Furthermore, it was found that the internal quantum efficiency of 4F9/2 decreases with increasing Dy3+ concentration.