Ge doping of GaN beyond the Mott transition
Ge doping of GaN beyond the Mott transition
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DOI：
10.1088/0022-3727/49/44/445301
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发表时间：
2016-11-09
影响因子：
3.4
通讯作者：
Monroy, E.
中科院分区：
文献类型：
--
作者：
Ajay, A.;Schoermann, J.;Monroy, E.
我们对等离子体辅助分子束外延生长的纤锌矿GaN薄膜中作为n型掺杂剂的锗进行了研究，在300 K时载流子浓度高达6.7×10²⁰ cm⁻³，远远超过莫特密度。在所研究的范围内，发现锗浓度和自由载流子密度与锗通量呈线性关系。所有的GaN:Ge层都呈现出具有原子台阶的光滑表面形貌，没有坑洼或裂纹的痕迹，并且样品的镶嵌性与锗浓度没有明显的依赖关系。GaN:Ge带隙随载流子浓度的变化与由于电子 - 电子和电子 - 离子相互作用以及伯斯坦 - 莫斯效应导致的带隙重整化的理论计算结果一致。
We present a study of germanium as n-type dopant in wurtzite GaN films grown by plasma-assisted molecular-beam epitaxy, reaching carrier concentrations of up to 6.7 x 10(20) cm(-3) at 300 K, well beyond the Mott density. The Ge concentration and free carrier density were found to scale linearly with the Ge flux in the studied range. All the GaN: Ge layers present smooth surface morphology with atomic terraces, without trace of pits or cracks, and the mosaicity of the samples has no noticeable dependence on the Ge concentration. The variation of the GaN: Ge band gap with the carrier concentration is consistent with theoretical calculations of the band gap renormalization due to electron-electron and electron-ion interaction, and Burstein-Moss effect.