Abstract We investigated the dark zone and transparent zone in GaN crystal grown by Na-flux method. The impurity concentration was detected by secondary-ion mass spectroscopy, and a higher concentration of O impurity was observed in the dark zone of GaN. As photoluminescence spectra were measured, the contrast between the yellow luminescence of transparent zone and green luminescence of dark zone was obtained, indicating the optical property of Na-flux grown GaN would be strongly influenced by the O impurity. Meanwhile, from the detail Raman measurements, the vacancy-related mode of peak P1 at ~420 cm−1 and peak P3 at ~670 cm−1 were observed. As a positive correlation between the carrier concentrations and the vacancy-related defects was found, the O impurity and the accompanying VGa was suggested to be the primary factor responsible for the above vacancy-related Raman modes which have been widely observed in the Na-flux grown GaN crystal.

中文翻译：

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Na-flux法生长GaN晶体不同生长区氧杂质的研究

摘要 我们研究了Na-flux法生长的GaN晶体中的暗区和透明区。通过二次离子质谱检测杂质浓度，在GaN暗区观察到较高浓度的O杂质。通过测量光致发光光谱，获得了透明区的黄色发光和暗区的绿色发光之间的对比，表明 Na-flux 生长的 GaN 的光学性质将受到 O 杂质的强烈影响。同时，从详细的拉曼测量中，观察到~420 cm-1 处的峰P1 和~670 cm-1 处的峰P3 的空位相关模式。发现载流子浓度与空位相关缺陷之间存在正相关关系，