基于变温霍尔效应方法的一类n-GaN位错密度的测量

发布时间：2018-06-02 10:09

本文选题：氮化镓 + 霍尔迁移率　；参考：《物理学报》2017年06期

【摘要】：结合莫特相变及类氢模型,采用浅施主能量弛豫方法,计算了一类常见n-Ga N光电子材料的载流子迁移率,给出了精确测定其刃、螺位错密度的电学方法.研究表明,对于莫特相变材料(载流子浓度超过1018cm~(-3)),以位错密度Ndis、刃螺位错密度比β、刃位错周围浅施主电离能εD1、螺位错周围浅施主电离能εD2为拟合参数的载流子迁移率模型与实验曲线高度符合,拟合所得刃、螺位错密度与X射线衍射法或化学腐蚀方法的测试结果也基本一致.实验结果表明,莫特相变材料虽然载流子浓度高、霍尔迁移率低,但其位错密度却并不一定高过载流子浓度低、霍尔迁移率高的材料,应变也无明显差异,因此,莫特相变与刃、螺位错密度及两类位置最浅的施主均无关系,可能是位置较深的施主或其他缺陷所致,需要比一般杂质带高得多的载流子浓度.该方法适合霍尔迁移率在0 K附近不为零,霍尔迁移率曲线峰位300 K左右及以上的各种生长工艺、各种厚度、各种质量层次的薄膜材料,能够对迁移率曲线高度拟合,迅速给出莫特相变材料的相关精确参数.
[Abstract]:Combined with Mott phase transition and hydrogen-like model, the carrier mobility of a class of common n-Ga N optoelectronic materials is calculated by using the shallow donor energy relaxation method. The electrical method for accurately measuring the edge and screw dislocation density is given. Research shows that For Mott phase change materials (carrier concentration over 1018 cm ~ (-1), carrier mobility model with dislocation density Ndiss, edge screw dislocation density ratio 尾, shallow donor ionization energy 蔚 D _ 1 around edge dislocation and shallow donor ionization energy 蔚 D _ 2 around screw dislocation as fitting parameters are obtained. The height of the experimental curve is consistent, The measured results of the fitted edge, the screw dislocation density and the X-ray diffraction method or chemical corrosion method are also consistent. The experimental results show that the dislocation density of Mott phase change material is not always higher than that of carrier concentration, although the carrier concentration is high and Hall mobility is low, and the strain of the material with high Hall mobility is not obviously different. The Mott phase transition is not related to the edge, screw dislocation density and the shallowest donor in both categories. It may be caused by the deeper donor or other defects and requires a much higher carrier concentration than the normal impurity band. This method is suitable for all kinds of growth processes where Hall mobility is not zero near 0 K, peak position of Hall mobility curve is about 300 K or above, thin film materials with various thickness and various quality levels can be highly fitted to the mobility curve. The exact parameters of Mott phase change material are given quickly.
【作者单位】：南昌大学科学技术学院;南昌大学材料科学与工程学院;上饶职业技术学院机械工程系;核技术应用教育部工程研究中心(东华理工大学);南昌大学现代教育技术中心;
【基金】：江西省自然科学基金(批准号:20151BAB207066) 南昌大学科学技术学院自然科学基金(批准号:2012-ZR-06)资助的课题~~
【分类号】：TN304.2

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