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

Abstract Al 2 O 3 /Y 3 Al 5 O 12 (YAG):Ce melt growth composites (MGCs) were grown by the vertical Bridgman (VB) method using an a -axis [1120] Al 2 O 3 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 Al 2 O 3 seed. In the MGC grown using the Al 2 O 3 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 Al 2 O 3 phase in the grown MGC corresponded to the a -axis Al 2 O 3 seed, while YAG phases with several different orientations were observed. The light-conversion properties of the MGCs grown using an a axis Al 2 O 3 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 Al 2 O 3 seed.