Pressure-controlled solution growth of bulk GaN crystals under high pressure

We have developed the pressure-controlled solution growth (PC-SG) method an d indicated the validity uf this method for the growth of GaN single crysta ls. We have investigated the effect of the supersaturation of nitrogen atom s on the size of a GaN single crystal and its morphology. GaN single crysta ls with a surface area of about 120 mm(2) and/or with good morphology were obtained at a rate of increase of nitrogen pressure less than 49 MPa/h. Str uctural and photoluminescence properties of GaN single crystals were examin ed and determined that these crystals with good morphology had good crystal linity. Furthermore, we have introduced a new high-pressure furnace and dev eloped the multi-crucible system. The GaN single crystal with a surface are a of 300 mm(2) was obtained by natural nucleation. The GaN crystal with 47 mm diameter, whose normal axis was the (0001) plane, could be grown on a sa pphire substrate.