POLARITY OF GAN SINGLE-CRYSTALS PREPARED WITH NA FLUX

The polarity of GaN platelet and prismatic single crystals grown in so dium Bur at 750 degrees C was investigated by X-ray single-crystal dif fraction. The smooth (000 (1) over bar) facet of platelet single cryst als corresponded to the N-terminated side. The (0001) facet on which s mall hillocks were observed corresponded to the Ga-terminated plane. T he c-axis direction from N to Ga atoms was defined as running from the pedion (flat base) to the pyramid (apex) of the prismatic crystals.