Crystal growth of gallium nitride in supercritical ammonia

Single crystals of gallium nitride were grown in supercritical ammonia at 400 degreesC and 2.4 kbar. Solubilization of the GaN feedstock was accomplished through the use of a mineralizer which is a mixture of KNH2 and KI. Two different crystal morophologies were obtained; rods and hexagonal plates. In both cases, plate growth occurs mainly perpendicular to the hexagonal axis. Although the largest crystals (0.5 x 0.2 x 0.1 mm(3)) isolated thus far are smaller than those obtained by high nitrogen pressure methods, supercritical ammonia holds the potential to be the low-temperature rival of the current methods. (C) 2001 Published by Elsevier science B.V.