Wavelength-tunable and thermally stable Li-α-sialon:Eu2+ oxynitride phosphors for white light-emitting diodes

Eu2+-activated Li-alpha-sialon is a promising yellow phosphor for white light-emitting diodes (LEDs). This letter reports that the emission of Eu2+ in Li-alpha-sialon can be tuned widely (563-586 nm) by tailoring the composition or controlling the Eu2+ concentration. The thermal stability of Li-alpha-sialon:Eu2+, relying a little on the composition and the Eu2+ concentration, remains high in a wide temperature range (25-200 degrees C). Moreover, the chromaticity of Li-alpha-sialon:Eu2+ does not shift with changes in temperature. Using a single Li-alpha-sialon:Eu2+ phosphor, highly efficient white LEDs (46-55 lm/W) with different color temperatures (3000-5200 K) can be fabricated. (c) 2006 American Institute of Physics.