Effect of electron distribution in InN films on infrared reflectance spectrum of longitudinal optical phonon-plasmon interaction region
Effect of electron distribution in InN films on infrared reflectance spectrum of longitudinal optical phonon-plasmon interaction region
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DOI：
10.1063/1.2875918
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发表时间：
2008-03
影响因子：
3.2
通讯作者：
Y. Ishitani;Xiaodong Wang;S. Che;A. Yoshikawa
中科院分区：
文献类型：
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作者：
Y. Ishitani;Xiaodong Wang;S. Che;A. Yoshikawa
在两个能区分析了InN/GaN结构纵向光学声子-等离子激元耦合模的高能和低能支的红外反射光谱。对于剩余电子密度小于5×1017 cm−3，薄膜厚度为0.7~4μm的样品，在200或250 cm−1以下的光谱表明，在InN/GaN界面附近存在电子积累，其片面电子密度为1013 cm−2。未发现表面电子积累对光谱的影响，这可能是由于表面电子的迁移率很小，约为10cm2/vs或更小所致。考虑到这种界面积累，得到了内部体区的电子密度。然而，对于具有较高电子密度和几微米厚度的样品，具有均匀电子密度的模型很好地再现了实验光谱。通过这个谱的拟合，我们提取了具有TH的样品的体区的电子性质。
The infrared reflectance spectra of InN∕GaN structures are analyzed in two energy regions for higher and lower energy branches of the longitudinal optical phonon-plasmon coupled modes. For samples with smaller residual electron density than 5×1017cm−3 and the film thickness of 0.7–4μm, the spectra down to 200 or 250cm−1 shows the existence of the electron accumulation with sheet electron density of 1013cm−2 in the vicinity of the InN∕GaN-interface. The effect of the surface electron accumulation on the spectra is not identified, which is possibly caused by the small mobility of the order of 10cm2∕Vs or less for the surface electrons. The electron density of the inside bulk region is obtained with account of this interface accumulation. However, for samples with higher electron density and thickness of several micrometers a model with uniform electron density well reproduce the experimental spectra. With this spectrum fitting we extract the electron properties inside the bulk region for samples with the th...