Intrinsic electron accumulation at clean InN surfaces
Intrinsic electron accumulation at clean InN surfaces
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DOI：
10.1103/physrevlett.92.036804
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发表时间：
2004-01-23
影响因子：
8.6
通讯作者：
Schaff, WJ
中科院分区：
文献类型：
--
作者：
Mahboob, I;Veal, TD;Schaff, WJ
用高分辨电子能量损失谱研究了洁净InN（0001）表面的电子结构。一个内在的表面电子积累层被发现存在，并解释在一个特别低的伽玛点导带最低的纤锌矿InN。因此，表面费米能级钉扎高的导带附近的伽马点，但附近的平均midgap能量，产生带电的施主型表面态与相关的向下带弯曲。能量损失谱的半经典介电理论模拟和电荷分布计算表明，表面态密度为2.5（+/-0.2 x10（13）cm（-2）），表面费米能级为1.64+/-0.10 eV，高于价带最大值。
The electronic structure of clean InN(0001) surfaces has been investigated by high-resolution electron-energy-loss spectroscopy of the conduction band electron plasmon excitations. An intrinsic surface electron accumulation layer is found to exist and is explained in terms of a particularly low Gamma-point conduction band minimum in wurtzite InN. As a result, surface Fermi level pinning high in the conduction band in the vicinity of the Gamma point, but near the average midgap energy, produces charged donor-type surface states with associated downward band bending. Semiclassical dielectric theory simulations of the energy-loss spectra and charge-profile calculations indicate a surface state density of 2.5 (+/-0.2)x10(13) cm(-2) and a surface Fermi level of 1.64+/-0.10 eV above the valence band maximum.