RF Plasma MBE生长GaN材料及特性研究

GaN GROWN BY RF PLASMA MBE AND STUDIES ON ITS PROPERTIES

用ＲＦＰｌａｓｍａ ＭＢＥ方法生长出了ＧａＮ 材料，它的Ｘ 射线衍射半峰宽为３３５ 秒，７７Ｋ 下ＰＬ发光峰半峰宽为２２ｍｅＶ，表明了材料具有较高的晶体质量。根据Ｘ射线衍射分析，位错密度约为７ ．３ ×１０８ｃｍ －２ 。用Ｓｉ 作为掺杂剂，所得载流子浓度可覆盖１０１７ － １０１９ｃｍ －３ 的范围。掺Ｓｉ ＧａＮ 的ＰＬ谱表明，Ｓｉ 的引入可提高材料的发光效率。

The growth of GaN on sapphire by RF plasma assisted molecular beam epitaxy (RF plasma MBE) is investigated with the object of optimizing the material quality. The small FWHM of x-ray diffraction rocking curve and 77K photoluminescence (335 arcsec and 22meV, respectively) show that the epitaxial GaN has good quality. Using mosaic model, the dislocation density in the GaN is estimated to be 7.3×10 8cm -2 . The optical properties of n-GaN are investigated for Si doping concentration ranging from 10 17 to 10 19 cm -2 . The intensity of the near -band-gap transition is found to increase monotonically as the doping concentration is increased.