Luminescence properties of full-color single-phased phosphors for white LEDs

A series of full-color single-phased phosphors for white LEDs (W-LEDs), in the system (Y, Ln)(2)GeO(5) (Ln = Tm, Tb, Eu), were prepared and their photoluminescence properties were characterized. The simultaneous incorporation of Eu(3+), Tb(3+) and Tm(3+) ions in Y(2)GeO(5) lattice can result in an integration of red, green, and blue emissions when being excited by ultraviolet light. Under excitation at 352 nm, the color tones of the (Y(0.95-x)Tm(0.01)Tb(x)Eu(0.04))(2)GeO(5) phosphors change from cool white to warm white by increasing the concentration of Tb(3+), while the intensities of Eu(3+) emissions increase. Indeed, in the case of co-doped systems, a very efficient energy that transfers from Tb(3+) to Eu(3+) occurs. The present phosphors can potentially be used for the high CRI and high luminous efficient white LEDs. (C) 2010 Elsevier B.V. All rights reserved.