Undoped GaN crystalline powders have been synthesized by the novel vapor phase method, in which two chemical reactions are utilized for the stages of seed formation and particle growth, respectively. The seed particles were formed by the reaction of vaporized Ga and NH_3, followed by growth of GaN on the seeds by the reaction of GaCl and NH_3. Single-phase GaN powders in the wurtzite form were produced by this method at the reaction temperature during the stage of particle growth (T_r) ranging from 800 to 1050°C. The structural and luminescent properties of the synthesized samples were characterized with a focus on the dependence on T_r. Significant increase of particle size and improved yields were achieved for the synthesis at T_r higher than 1000 °C. Photoluminescence property is discussed in terms of the mechanism of particle growth.
展开▼
