Characterization of YAG Phosphor by Electrophoretic Deposition Technique

In our experiments, by varying the concentration of YAG phosphor, the deposition thickness of YAG phosphor plate can be controlled approximately 16 to 40 micrometer under a bias voltage of 200 V. By combining the blue LED light and the above EPD YAG phosphor plate, the white light with a correlated colour temperature (CCT) can be achieved and varied from 3800 K to 6000 K. In the conventional dispense package, the larger CCT variation was always found and varied from 80 K to 1500 K which is related to the packing density. However, in our EPD YAG case, the uniform white light was achieved easily, i.e. that is the lower CCT variation. In addition, the external extraction efficiency was also found higher than the tradition white LED.