Investigation of TiO2 and Ce3+-activated TiO2 particles on optical properties of the PMMA embedded YAG: Ce3+ and LuAG: Ce3+

Ce3+ activated garnets; LuAG and YAG are extensively used in lighting applications, electronics, and display technologies. Both of the phosphors have been studied many times to increase their brightness and provide a red -shift in their emission maximum towards warmer colors for potential white light emitting diode (WLED) ap-plications. In this work, binary blends of the LuAG: Ce3+ with the micro-scale TiO2 and Ce3+-equipped TiO2 particles were prepared and tested in terms of photoluminescence characteristics in a polymethyl methacrylate (PMMA) matrix. Similar work was also performed for the YAG: Ce3+and its TiO2-based composites. Blue -wavelength excitation and emission performances as well as decay characteristics of the phosphors were investigated in detail. When excited by blue wavelengths, the TiO2 blends of the LuAG: Ce3+ and YAG: Ce3+ exhibited strong enhancement in emission intensities extending to 2.80 and 2.20 fold in comparison to their additive-free forms. Additionally, 32 and 66 nm of red shifts were measured in the emission maximum of the TiO2-based blends, respectively. The decay time measurements performed in the microsecond time scale revealed parallel variations to the increases observed in the intensities. The distinguishable enhancement observed in the quantum efficiency of the phosphors by using cost-effective TiO2 particles can be concluded as a remarkable development. Additionally, the ability of the phosphor blends to be excited with simple blue LEDs looks very promising for future lighting applications.