Photoluminescence and resonant energy transfer from Tb3+ to Eu3+ in Tb3Ga5O12:Eu3+ garnet phosphor

Abstract

Eu3+-activated Tb3Ga5O12 (TGG) phosphor was synthesized by metal-organic deposition and its luminescence properties were reported in detail. The (Tb1−xEux)3Ga5O12 phosphor was synthesized from a mixture of organic gallium solution and acetic acid dissolved with TbCl3/Eu2O3. The X-ray diffraction analysis indicated that the synthesized phosphor was cubic garnet structure. The luminescence properties of the TGG:Eu3+ phosphor were investigated using photoluminescence (PL) analysis, PL excitation (PLE) spectroscopy, and PL decay measurement. The effects of Eu3+ concentration on the PL properties were studied between x=0 and 0.14, and the strongest PL emission was observed at x~0.002. The PLE and PL decay characteristics showed the occurrence of an efficient energy transfer from the host (Tb3+) to Eu3+ in the TGG:Eu3+ phosphor. The increase in the PL intensity with increasing temperature was observed and analyzed on the basis of a simplified charge transfer along with the inclusion of conventional thermal quenching. The detailed energy-level scheme for the Tb3+ and Eu3+ ions in the TGG host was also determined from these PL and PLE spectra.