Department of Physics, Soochow University, 1 Shizi Street, Suzhou 215006, People's Republic of China.
J Phys Condens Matter. 2012 Jun 27;24(25):255303. doi: 10.1088/0953-8984/24/25/255303. Epub 2012 May 25.
We investigate charge transport across metal-molecule-metal junctions, i.e. hexagonal and triangular nanographene molecular layers sandwiched between Pt and Pd thin films, as measured by ballistic-electron-emission spectroscopy (BEEM). The measured shape of current-voltage curves cannot be explained in the framework of existing BEEM theories of bulk inorganic semiconductors. We develop a tight-binding model for the BEEM process and propose that the energetic dispersion of molecular layers and the dephasing effect due to the interface states account for the anomalous BEEM current-voltage behavior and play an important role in determining the shape of the curve. The electron-phonon scattering can also affect the shape of current-voltage curves.
我们通过弹道电子发射光谱（BEEM）研究了金属-分子-金属结（即夹在 Pt 和 Pd 薄膜之间的六方和三角纳米石墨烯分子层）中的电荷输运。通过 BEEM 测量得到的电流-电压曲线的形状不能用现有的体无机半导体的 BEEM 理论来解释。我们为 BEEM 过程开发了一个紧束缚模型，并提出分子层的能量色散和界面态引起的退相效应解释了异常的 BEEM 电流-电压行为，并在确定曲线形状方面起着重要作用。电子-声子散射也会影响电流-电压曲线的形状。
