State Key Lab of Crystal Materials, Shandong University, Jinan, 250100, P.R. China.
Department of Materials Science and Engineering, Qilu University of Technology, Jinan 250353, P. R. China.
Sci Rep. 2014 Feb 26;4:4179. doi: 10.1038/srep04179.
GaN crystals without cracks were successfully grown on a MOCVD-GaN/6H-SiC (MGS) substrate with a low V/III ratio of 20 at initial growth. With a high V/III ratio of 80 at initial growth, opaque GaN polycrystals were obtained. The structural analysis and optical characterization reveal that stress has a great influence on the growth of the epitaxial films. An atomic level model is used to explain these phenomena during crystal growth. It is found that atomic mobility is retarded by compressive stress and enhanced by tensile stress.
成功地在初始生长时 V/III 比为 20 的低 GaN/MOCVD-GaN/6H-SiC (MGS) 衬底上生长出无裂纹 GaN 晶体。而在初始生长时 V/III 比为 80 时，则得到不透明的 GaN 多晶。结构分析和光学特性表明，在薄膜生长过程中，应变速率对其生长有很大的影响。利用原子级模型来解释这些在晶体生长过程中的现象。结果表明，压应力会阻碍原子迁移，而张应力则会增强原子迁移。
