Song Hyunwook, Lee Hyoyoung, Lee Takhee
Department of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea.
Ultramicroscopy. 2008 Sep;108(10):1196-9. doi: 10.1016/j.ultramic.2008.04.016. Epub 2008 May 7.
We report on a tip-loading force-dependent tunneling behavior through alkanethiol self-assembled monolayers formed in metal-molecule-metal junctions, using conducting atomic force microscopy. The metal-molecule contacts were formed by placing a conductive tip in a stationary point contact on alkanethiol self-assembled monolayers under a controlled tip-loading force. Current-voltage characteristics in the alkanethiol junctions are simultaneously measured, while varying the loading forces. Tunneling current through the alkanethiol junctions increases and decay coefficient beta(N) decreases, respectively, with increasing tip-loading force, which results from enhanced intermolecular charge transfer in a tilted molecular configuration under the tip-loading effect.
我们使用导电原子力显微镜，报道了通过金属 - 分子 - 金属结中形成的烷硫醇自组装单分子层的尖端加载力依赖性隧穿行为。金属 - 分子接触是通过在可控的尖端加载力下，将导电尖端置于烷硫醇自组装单分子层上的固定点接触处形成的。在改变加载力的同时，同步测量烷硫醇结中的电流 - 电压特性。通过烷硫醇结的隧穿电流分别随着尖端加载力的增加而增加，衰减系数β(N)减小，这是由于在尖端加载效应下倾斜分子构型中分子间电荷转移增强所致。
