Synthesis and photoluminescence properties of novel yellow-emitting Ba2Gd5−xDyxB5O17 phosphors
Single phase yellow-emitting Dy3+ ions doped Ba2Gd5B5O17 phosphors were synthesized by solid-state reaction technique at high temperature. The phase identification and photoluminescence properties of as-prepared phosphors were characterized by X-ray diffraction patterns, excitation and emission spectra, decay curves and temperature-dependent luminescence spectral measurements. Under 276 and 354 nm near-UV excitations, the studied phosphors exhibited two intense emission bands in blue (486 nm) and yellow (575 nm) regions due to the magnetic dipole (4F9/2→6H15/2) and electric dipole (4F9/2→6H13/2) transitions, respectively. The optimal doping concentration of Dy3+ ions was found to be x = 0.07 for Ba2Gd5−xDyxB5O17 phosphors. Under 354 nm excitation, the color coordinates (x, y) of Ba2Gd4.93Dy0.07B5O17 phosphor were located in the yellow region of Commission International de I-Eclairage 1931 diagram and hence it can be used as a potential yellow component in the fabrication of white light-emitting diodes. Furthermore, the decay curves were fitted to double-exponential function to find the excited state lifetimes of Dy3+ ions. Besides, the temperature-dependent luminescence measurements were made to explore the thermal stability and activation energy of the concentration-optimized Ba2Gd4.93Dy0.07B5O17 phosphor. The results obtained from the present investigation were discussed in detail and compared with the similar reported literatures.
This work was supported by the National Natural Science Foundation of China (No. 51502190), the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi, and the Open Fund of the State Key Laboratory of Luminescent Materials and Devices (South China University of Technology, No. 2017-skllmd-01).