Characterization of multiple carriers in GaN using variable magnetic-field hall measurements
Characterization of multiple carriers in GaN using variable magnetic-field hall measurements
复制标题
使用可变磁场霍尔测量表征 GaN 中的多个载流子
DOI：
10.1007/s11664-004-0193-8
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发表时间：
2004
影响因子：
2.1
通讯作者：
J. Sizelove
中科院分区：
文献类型：
--
作者：
C. Swartz;R. Tompkins;T. Myers;D. Look;J. Sizelove
对氢化物气相外延（HVPE）生长的两个厚GaN样品进行了变磁场霍尔效应测量，一个是独立的，一个是附着在蓝宝石衬底上的。结果与使用更标准的单磁场霍尔测量得到的结果进行了比较。在这两个样品中，第二个低迁移率电子被指出显著影响单场霍尔测量的解释，特别是在低温下。利用对变场霍尔数据的拟合提取散货船，可以更准确地确定散货船电性能的温度依赖性，从而确定基本物理参数。此外，本文首次在GaN上报道的定量迁移谱分析（QMSA）技术表明，体电子的迁移率持续且显著地扩展，可能与样品厚度有关。因此，即使是本研究中基于多载波拟合（MCF）分析建模而得到的“改进”结果，也应该带着一些怀疑来看待，因为它们显然代表了电不均匀样本的平均值。
Variable magnetic-field Hall-effect measurements were performed on two thick GaN samples grown by hydride vapor-phase epitaxy (HVPE), one freestanding and one attached to the sapphire substrate. Results are compared to those obtained using the more standard, single magnetic-field Hall measurements. In both samples, a second low-mobility electron was indicated that significantly influenced interpretation of single-field Hall measurements, particularly at low temperatures. Extraction of the bulk carrier using fits to the variable-field Hall data allowed a more accurate determination of the temperature dependence of the bulk electrical properties and, hence, basic physical parameters. In addition, the quantitative mobility-spectrum analysis (QMSA) technique, reported here for the first time on GaN, indicated a continuous and significant spread in mobility for the bulk electron, likely with sample thickness. Thus, even the “improved” results, based on modeling the multiple-carrier fitting (MCF) analysis, obtained in this study should be viewed with some suspicion, as they clearly represent an average over an electrically inhomogeneous sample.