کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5424725 | 1395834 | 2008 | 7 صفحه PDF | دانلود رایگان |
The distance dependence of the tunneling current has been measured for the Au(1Â 1Â 1)/0.1Â M H2SO4 interface over a wide potential range. From these data an effective barrier height (EBH) for the tunneling process through the electrochemical double layer has been determined, the distance dependence of which shows a marked potential dependence. An oscillatory behavior of the EBH with distance s between electrode surface and tip is observed only for the charged interface, while at the potential of zero charge a monotonous increase in the EBH with s is found until a plateau is reached, similar to the situation in UHV, and almost identical to the behavior of Au(1Â 1Â 1) in air. Absolute values for the tunnel gap have been obtained with the help of DFT calculations. A detailed DFT-derived model of the negatively charged interface is presented, which allows for a direct correlation between charge densities and EBH extrema.
Journal: Surface Science - Volume 602, Issue 7, 1 April 2008, Pages 1401-1407