Probing semiconductor gap states with resonant tunneling.
Probing semiconductor gap states with resonant tunneling.
复制标题
通过谐振隧道探测半导体能隙态。
DOI：
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发表时间：
2006
影响因子：
8.6
通讯作者：
G. Döhler
中科院分区：
文献类型：
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作者：
S. Loth;M. Wenderoth;L. Winking;R. Ulbrich;S. Malzer;G. Döhler
用低温扫描隧道显微镜(STM)研究了GaAs{110}表面下耗尽层的隧穿输运。观察到的负微分电导是由于单个浅受主通过耗尽层的隧穿几率的共振增强。扫描隧道显微镜实验在适当的偏置电压下，探测到了GaAs禁带中的衰减态。能量分辨光谱和空间分辨光谱表明，浅受主的各向异性对比度图样只出现在这一特定的输运通道上。我们的发现表明，复杂的能带结构导致了观察到的与闪锌矿对称性有关的各向异性。
Tunneling transport through the depletion layer under a GaAs {110} surface is studied with a low temperature scanning tunneling microscope (STM). The observed negative differential conductivity is due to a resonant enhancement of the tunneling probability through the depletion layer mediated by individual shallow acceptors. The STM experiment probes, for appropriate bias voltages, evanescent states in the GaAs band gap. Energetically and spatially resolved spectra show that the pronounced anisotropic contrast pattern of shallow acceptors occurs exclusively for this specific transport channel. Our findings suggest that the complex band structure causes the observed anisotropies connected with the zinc blende symmetry.