Growth of Mg-doped GaN micro-crystals using MgCl_2 in direct reaction of Ga and NH_3

摘要

Mg-doped GaN micro-crystals were prepared by using the direct reaction of liquid Ga with NH_3 gas. Magnesium chloride (MgCl_2) was employed as an Mg source in the growth. The growth rate and size of the Mg-doped GaN micro-crystals increased with the amount of MgCl_2. The micro-crystals grew with a hexagonal structure. A broad band emission peak was observed at ～2.7 eV and its intensity increased with Mg concentration in the GaN micro-crystals. It seemed that the increase of the growth rate and the size of the micro-crystals were due to the presence of Mg and Cl species in the growth reaction. Catholuminescence also showed the blue emission at 2.85 eV due to a deep Mg-related complex.