Influence of 3d-Transition-Metal Additives on Single Crystal Growth of GaN by the Na Flux Method

Abstract

The influence of 3d-transition-metal additives (Cr, Mn, Fe, Co and Ni) on crystal growth of GaN at 750–850°C by the Na flux method was investigated. In the case of Cr addition, CrN single crystals were deposited and no significant difference in the crystal growth of GaN was found. In the case of Mn addition, growth of GaN single crystals in the -c direction was enhanced and prismatic crystals were obtained. Mn of 0.10–0.35 at.% was contained in GaN crystals. The Mn-doped GaN crystals were red or orange in color and showed Curie-like paramagnetism. Fe, Co and Ni additives also enhanced the growth of prismatic crystals. These transition-metal elements as well as Cr were not detected in the GaN crystals by inductively coupled plasma (ICP) atomic emission spectroscopy. Colorless transparent prismatic crystals having 1.5 mm length were prepared using the Ni additive.