Effects of Pr3+ -activated BaZrGe3O9@TiO2 phosphor compound on light emitting diodes validated by computer simulation

Abstract

The Pr³⁺ -doped BaZrGe₃₉ gallogermanate phosphors are reported to have a well-defined successive deep defect structure that effectively mitigates thermal carrier fading. This phosphor also presents a red emission with a peak at 615 nm, originating from the Pr³⁺ transtition from ¹D₂ to ³H₄. We investigated the impact of Pr³⁺ -activated BaZrGe3O9 (referred to as BZG:Pr) on the lighting characteristics of light emitting diodes (LED) packages in this paper. By combining BZG:Pr with TiO₂ particles and silicone, we produced a phosphor layer (designated as BZG:Pr@TiO₂). The optical performance of the resulting LED was systematically examined by varying the TiO₂ doping percentage. Our findings reveal that the incorporation of the BZG:Pr phosphor enhances the red spectral component, thereby contributing to improved homogeneity in color distribution. However, a progressive increase in TiO₂ content within the phosphor layer corresponds to diminishing luminous output and decreased chromatic rendering efficiency of the LED. Employing a lower concentration of TiO₂ proves advantageous, as it capitalizes on the scattering-enhancing attributes while leveraging the red emission of the BZG:Pr phosphor. This synergistic approach yields a favorable balance between luminosity and color quality, enhancing the LED’s overall performance.