The growth of Al2O3/YAG:Ce melt growth composite by the vertical Bridgman technique using an a-axis Al2O3 seed

• We studied the VB growth of Ce-doped MGC using an a-axis [112̄0] Al2O3 seed.
• A crack-free MGC ingot could be grown from the Al2O3 seed.
• The orientation of the Al2O3 phase in the MGC is retained from the Al2O3 seed.
• YAG phases with several different orientations were observed.
• The optical properties of the MGCs were similar to those grown using an MGC seed.

Al2O3/Y3Al5O12 (YAG):Ce melt growth composites (MGCs) were grown by the vertical Bridgman (VB) method using an a-axis [112̄0] Al2O3 seed, and the crystallographic orientations and optical properties of the grown MGCs were investigated. It was found that a crack-free MGC ingot could be grown from the Al2O3 seed. In the MGC grown using the Al2O3 seed, the position of the seeding interface was almost the same to the initial position of the top of the seed. By means of electron backscatter diffraction (EBSD) analysis, it was found that the crystallographic orientation of the Al2O3 phase in the grown MGC corresponded to the a-axis Al2O3 seed, while YAG phases with several different orientations were observed. The light-conversion properties of the MGCs grown using an a axis Al2O3 seed for application to white light emitting diodes (LEDs) were quite similar to those grown using an MGC seed. It was also found that it was possible to grow larger diameter, 2-in., Ce-doped MGC ingots with similar crystallographic properties with the VB method using a small Al2O3 seed.