{
  "id": "1704.03001",
  "version": "v1",
  "published": "2017-04-10T18:21:53.000Z",
  "updated": "2017-04-10T18:21:53.000Z",
  "title": "Electron Mobility in Polarization-doped Al$\\mathrm{_{0-0.2}}$GaN with a Low Concentration Near 10$\\mathrm{^{17}}$ cm$\\mathrm{^{-3}}$",
  "authors": [
    "Mingda Zhu",
    "Meng Qi",
    "Kazuki Nomoto",
    "Zongyang Hu",
    "Bo Song",
    "Ming Pan",
    "Xiang Gao",
    "Debdeep Jena",
    "Huili Grace Xing"
  ],
  "comment": "6 figures. Submitted to Applied Physics Letters",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "In this letter, carrier transport in graded Al$\\mathrm{_x}$Ga$\\mathrm{_{1-x}}$N with a polarization-induced n-type doping as low as ~ 10$\\mathrm{^{17}}$ cm$\\mathrm{^{-3}}$ is reported. The graded Al$\\mathrm{_x}$Ga$\\mathrm{_{1-x}}$N is grown by metal organic chemical vapor deposition on a sapphire substrate and a uniform n-type doping without any intentional doping is realized by linearly varying the Al composition from 0% to 20% over a thickness of 600 nm. A compensating center concentration of ~10$\\mathrm{^{17}}$ cm$\\mathrm{^{-3}}$ was also estimated. A peak mobility of 900 cm$\\mathrm{^2}$/V$\\mathrm \\cdot$s at room temperature is extracted at an Al composition of ~ 7%, which represents the highest mobility achieved in n-Al$\\mathrm{_{0.07}}$GaN with a carrier concentration ~10$\\mathrm{^{17}}$ cm$\\mathrm{^{-3}}$. Comparison between experimental data and theoretical models shows that, at this low doping concentration, both dislocation scattering and alloy scattering are significant in limiting electron mobility; and that a dislocation density of <10$\\mathrm{^7}$ cm$\\mathrm{^{-2}}$ is necessary to optimize mobility near 10$\\mathrm{^{16}}$ cm$\\mathrm{^{-3}}$. The findings in this study provide insight in key elements for achieving high mobility at low doping levels in GaN, a critical parameter in design of novel power electronics taking advantage of polarization doping.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-04-10T18:21:53.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "electron mobility",
      "low concentration",
      "metal organic chemical vapor deposition",
      "novel power electronics",
      "n-type doping"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}