The Evaluation of Phosphor for White LEDs by CL Image

Phosphor plays a key role to obtain white light as for blue LED + phosphor and near ultraviolet LED + phosphors. In order to improve high bright white LEDs, it is necessary that the whole phosphor particle emits light homogeneously. When measuring with CL the phosphor used as white LED, the area which does not emit light in phosphor particle can be observed. CL system is used for evaluation of non-luminescent area to improve luminescent efficiency and characteristics.