Structure, tunable luminescence and energy transfer in Tb(3+) and Eu(3+) codoped Ba(3)InB(9)O(18) phosphors

The borate Ba(3)InB(9)O(18) (BIBO) is a promising host material for phosphors. A series of Tb(3+) and Eu(3+) codoped Ba(3)InB(9)O(18) phosphors were synthesized. Based on the Rietveld method, structure refinement of the codoped BIBO phosphor was carried out. Then, the luminescence properties of BIBO:Tb(3+), Eu(3+) phosphors were extensively investigated under ultraviolet (UV) and vacuum ultraviolet (VUV) excitation. The measured PL spectra and decay times evidenced that energy transfer occurs between the Tb(3+) and Eu(3+) ions. The energy-transfer mechanism from Tb(3+) to Eu(3+) in Ba(3)InB(9)O(18) is dominated by electric multipolar interactions, with the critical distance calculated to be 10.97 Å. The temperature sensitivity of the Tb(3+) and Eu(3+) codoped sample under VUV was also investigated at the low temperature range from 25 K to 298 K. The emission color could be tuned from green to the red region by adjusting the concentration of codoped ions. The results indicate that the BIBO-based phosphors are valuable candidates for applications in the display and lighting fields.