Growth of Prismatic GaN Single Crystals with High Transparency on Small GaN Seed Crystals by Ca–Li-Added Na Flux Method

Abstract

The addition of Ca–Li to Na flux was attempted in order to control the growth habit and further improve transparency of GaN crystals. As a result, the growth habit changed to prism shape by the addition of Ca. Furthermore, we succeeded in growing prismatic GaN crystals with high transparency by adding appropriate amounts of Ca and Li to the flux. The optical absorption coefficient at 450 nm wavelength obtained from the crystal was 1.07 cm-1. This result suggests that the addition of Ca–Li to Na flux is a promising method of growing transparent GaN single crystals.