Pr³⁺ doped LaTiNbO₆ as a single phosphor for white LEDs

A structurally disordered host crystal, LaTiNbO₆, has been doped with the Pr³⁺ ions emitting at two wavelength regions that could be mixed to give out white light. In agreement with the structural design, the samples showed inhomogeneously broadened transition lineshape arising from the disorder, which is not only efficient for the absorption of blue LED sources, but also insensitive to temperature variations. Aeschynite-structured LaTiNbO₆ allowed doping of up to 100% Pr³⁺ without phase segregation. The samples gave out two clusters of dominant emissions peaked at 490 nm (³P₀ → ³H₄) and 609 nm (³P₀ → ³H₆), respectively, whose relative intensities could be tuned by the doping level to give a desired chromaticity.