The phosphor’s optical properties–chromaticity coordinate relationship of phosphor converted white LEDs

Based on optical ray-tracing simulations we discuss the effect of the extinction coefficient and the quantum efficiency of the phosphors on the angular homogeneity of the white light emitted from phosphor converted light-emitting diodes. In particular variations of the extinction coefficient are prone to affect diverse CIE chromaticity coordinates for different viewing angles. Contrarily, the impact of the quantum efficiency on angle dependent variations of the chromaticity coordinates turns out to be of minor importance.