Vertical Bridgman growth of Al2O3/YAG:Ce melt growth composite

The vertical Bridgman (VB) method was investigated as a way to grow Al2O3/YAG:Ce melt growth composite (Ce-doped MGC), an attractive candidate material for blue-to-yellow light conversion. Crucibles made from molybdenum (Mo) and iridium (Ir), whose linear thermal expansion coefficients are significantly different, were examined as potential solutions to the problem of crucible reuse in the growth of large Ce-doped MGC ingots. It was found that Ce-doped MGC ingots grown in Mo crucibles could easily be released nondestructively, while ingots grown in Ir crucible could not. We confirmed that the inside diameter of a Mo crucible is always larger than the diameter of the Ce-doped MGC ingots formed in it, at all temperatures from the melting point to room temperature during the entire cooling process. We also confirmed that larger diameter, 2- ancl 3-in., Ce-doped MGC ingots with the same orientation as the seed could be grown using Mo crucibles with the VB method. We conclude that Mo crucibles, with a smaller linear thermal expansion coefficient than that of Ce-doped MGC at all temperatures from the melting point to room temperature are useful for growing large ingots and allowing crucible reuse. (C) 2015 Elsevier B.V. All rights reserved