Dipole-dipole energy transfer mechanism to the blue-white-red color-tunable emission presented by CaYAlO4:Tb3+,Eu3+ biocompatibility material obtained by the simple and low cost of chemical route

Abstract

Color tunable blue-white-red emitting CaY0.99-xTb0.01EuxAlO4 phosphors were prepared by an easy and low-cost chemical route using citric acid as precursor. The structural and morphological properties were evaluated by XRD and SEM techniques. The photoluminescence spectra and decay curves under excitation at 352 nm reveals the energy transfer process from Tb3+ to Eu3+. The dependence of temperature on energy transfer was evaluated, indicating higher efficiency as the temperature increases The dominant mechanism was demonstrated to be dipole-dipole type. By adjusting the excitation wavelength, the color emission of CaYAlO4:Tb3+,Eu3+solids can be tuned from blue to red, through white light. The cell viability of this materials was performed in the saccharomyces cerevisiae medium culture observing the biocompatibility with 160 and 320 μg/mL of concentration. In parallel the white emission performance was analyzed by determining the CIE coordinates and color correlated temperature (CCT). The CaY0.985Tb0.01Eu0.005AlO4 material showed CIE coordinates (0.327, 0334) and CCT = 5755 K, making this material an example of single-phase white emitting system.