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arXiv 1503.00646cond-mat.mes-hallcond-mat.mtrl-sci
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扫描隧道光谱揭示了硅悬空键电荷态跃迁

Scanning tunneling spectroscopy reveals a silicon dangling bond charge state transition

Hatem Labidi, Marco Taucer, Mohammad Rashidi, Mohammad Koleini, Lucian Livadaru, Jason Pitters, Martin Cloutier, Mark Salomons, Robert A. Wolkow

摘要:

利用低温扫描隧道显微镜(LT-STM)研究了氢封端硅(100)表面上的单悬挂键(DB)。通过研究不同退火温度下制备的样品,我们建立了次表面砷掺杂对DB电子性能的关键作用。我们表明,当近表面浓度的掺杂剂耗尽作为结果的$1250°C$闪光退火,一个单一的DB表现出尖锐的导电步骤,在其I(V)光谱,这不是由于状态效应的密度,而是对应于DB电荷态转变。该转变的电压位置与DB在不同电荷状态下的STM图像中的偏压依赖性变化完全相关。密度泛函理论(DFT)计算通过显示DB-掺杂剂距离对DB状态的影响,进一步突出了次表面掺杂剂对DB性质的作用。我们讨论了可能的理论模型的电子传输通过DB,可以解释我们的实验观察。

英文摘要:

We report the study of single dangling bonds (DB) on the hydrogen terminated silicon (100) surface using a low temperature scanning tunneling microscope (LT-STM). By investigating samples prepared with different annealing temperatures, we establish the critical role of subsurface arsenic dopants on the DB electronic properties. We show that when the near surface concentration of dopants is depleted as a result of $1250°C$ flash anneals, a single DB exhibits a sharp conduction step in its I(V) spectroscopy that is not due to a density of states effect but rather corresponds to a DB charge state transition. The voltage position of this transition is perfectly correlated with bias dependent changes in STM images of the DB at different charge states. Density functional theory (DFT) calculations further highlight the role of subsurface dopants on DB properties by showing the influence of the DB-dopant distance on the DB state. We discuss possible theoretical models of electronic transport through the DB that could account for our experimental observations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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