Effect of Laser Drilling on the Microstructure and Luminescence of YAG :Ce,Si Phosphor Ceramics

Y ₃ Al ₅ O ₁₂ :Ce,Si ( YAG :Ce,Si) phosphor ceramics prepared by a solid‐state reaction method were drilled with an array of holes in a diameter of 100 μm. The laser‐induced heat‐affected zone surrounding the laser‐drilled holes with a ring width of about 150 μm was analyzed to consist of Y ₄ Al ₂ O ₉ , YA lO ₃ , and Al ₂ O ₃ phases, induced by the phase transformations from the YAG melt during laser drilling. Photoluminescence study of the YAG :Ce,Si phosphor ceramic indicated variable blue light transmission and yellow emission, suggesting the potential of tuning blue/yellow intensity ratio as well as precise color control of light‐emitting diodes.