Recently much work has been directed at the growth of epitaxial layers of the group III nitrides because of their potential application in the manufacture of blue LEDs and laser diodes. These layers have been deposited on such materials as sapphire and silicon carbide. Because of the large lattice mismatch of these materials with the nitrides, a large number of defects are generated. If large single crystals of the group III nitrides could be grown, they could be used as the substrate for these devices, resulting in a significant improvement in efficiency. The objective of our proposal is to use our new growth technique, the PTFG method, to grow large crystals of GaN. This technique can also be used for the other group III nitrides such as AlN and InN as well as for many other materials that are difficult to grow.Anticipated Benefits/Commercial Applications: There is much interest in blue laser diodes and LEDs. The group III nitrides are the most attractive materials for this application. The ideal substrate is single crystal wafers of the material to be grown but single crystals of appropriate size are not available. By successfully completing our program, substrates will become available that will make these devices commercially possible.
