Influence of gas composition on the synthesis of gallium nitride powders by two‐stage chemical vapor method

Abstract

AbstractThe systematic characterization of undoped GaN powders was carried out focusing on the composition of gases at the second stage of particle growth in the two‐stage chemical vapor synthesis. The particle growth proceeded on the surface of GaN seed particles transported from the first stage with sources of GaCl and NH3 at 1000 °C. The GaN particles grew very fast at the second stage, and their size increased monotonically with increasing partial pressure of GaCl (P (GaCl)). The photoluminescence (PL) property and the crystallinity tended to decrease with P (GaCl), whereas they were improved for higher partial pressures of NH3. Based on these results, we have shown that both of high‐rate growth and excellent PL property of GaN particles can be achieved by the two‐stage chemical vapor synthesis. Addition of H2 to the ambient gas caused degradation of the luminescence property and the crystalline quality as well as decrease in the particle size. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)