The Phase and crystal-growth study of group-III nitrides in a 2000C at 20 GPa region

Saito, Hiroyuki; Utsumi, Wataru; Kaneko, Hiroshi; Aoki, Katsutoshi

We have performed the synthesis study of group-III nitride crystals using a cubic-anvil-type large volume high pressure apparatus. Bulk crystals of the nitride compounds, which are key materials for developing optoelectronic and high-power/ frequency devices, can hardly be prepared by the conventional crystal growth technique such as the Bridgman method since they decompose on heating at ambient pressure before reaching the melting points. Appling pressure is expected to suppress decomposition reaction and consequently allow crystal growth from their melts. I will talk about the crystal growth of GaN and AlGaN under high pressure, and phase stability of InN under high pressure and temperature.