Electronic Properties of Nanoscale Metal/Silicon Interfaces and of Low-Dimensional Metal Clusters on Silicon Surfaces under Electrochemical Conditions

该项目将首先关注纳米级金属/ n-Si(111),（110）和（100）金属团簇界面的制备和电子特性的研究，即接触，直径低于20 nm，最好在0.3至5 nm之间。Co, Pb， Cu和Au团簇作为磁性/非磁性金属和能势在n-Si平带电位以下，周围和之上的系统的例子将被研究。基于这些结果，应利用金属团簇/n-Si界面的电子特性（在n-Si空间电荷层中的电子积累或耗尽）来精确调节单个金属团簇与n-Si衬底的电子系统耦合。因此，由于与衬底的电子耦合变化，个体的低维金属团簇的电子特性将被研究。准备和所有的研究将在最清洁的条件下，在固体/液体界面上，在使用不特别吸附的阴离子的电解质中，在脱氧电解质中，在黑暗中进行。金属团簇的制备将通过局部电沉积和非局部电沉积来实现。应用于研究的技术将是原位扫描隧道显微镜（STM），原位距离和电压隧道光谱（DTS和VTS），利用隧道显微镜尖端和金属团簇之间的量子化电导通道进行原位电子传输测量，以及纳米级金属团簇和电子隔离金属团簇下方空间电荷层的理论建模。我们将对单个纳米肖特基触点的电子特性有一个全面的了解，我们将通过局部电沉积的方法研究不同尺寸和距离的纳米二极管的不同集成来研究相互作用效应，我们将通过适当的电流/电压曲线计算来检验热离子发射模型的适用性。通过选择几种模型分子来研究各种吸附分子对测量结果的影响。单金属团簇的电子特性，但改变其与n-Si衬底的电子耦合将通过原位隧道光谱进行研究，最终在非水电解质中提供增加的双层范围，可用于电压隧道光谱。该项目的主要成果预计将在纳米电子学、催化或纳米传感器应用等领域产生重大影响。

The project will first be concerned with the preparation and investigation of the electronic properties of nanoscale metal / n-Si (111), (110), and (100) interfaces for metal cluster, i. e. contact, diameters below 20 nm, preferably between 0.3 and 5 nm. Co, Pb, Cu and Au clusters as examples for magnetic/non - magnetic metals and systems with Nernst potentials below, around, and above the n-Si flatband potentials shall be investigated. Based on these results, the electronic properties of metal cluster/n-Si interfaces (at electron accumulation or depletion in the n-Si space charge layer) shall be exploited to precisely adjust the coupling of the electron system of individual metal clusters to their n-Si substrate. Thus, the electronic properties of individual, low-dimensional metal clusters due to a variation in the electronic coupling to a substrate shall be studied. Preparation and all investigations will be performed in-situ at solid/liquid interfaces at utmost cleanliness conditions, in electrolytes using anions which do not adsorb specifically, in deaerated electrolytes, and in the dark . The preparation of metal clusters will be achieved by localized and delocalized electrodeposition. The techniques applied for the investigations will be in-situ Scanning Tunneling Microscopy (STM), in-situ Distance and Voltage Tunneling Spectroscopy (DTS and VTS), in-situ electron transport measurements utilizing quantized conductance channels between tunneling microscope tip and metal cluster, as well as theoretical modelling of the space charge layer underneath the nanoscale metal clusters and of electronically isolated metal clusters. A comprehensive understanding of the electronic properties of individual nanoscale Schottky contacts shall be derived, interaction effects shall be investigated by studding different ensembles of a few nanodiodes fabricated with denned size and distances by localized electrodeposition, and the applicability of the thermionic emission model shall be tested by appropriate calculations of current/voltage curves. The effects of various adsorbed molecules on the measurements shall be studied by choosing several model molecules. Electronic properties of single metal clusters at denned, but variing electronic coupling to their n-Si substrate shall be investigated by in-situ tunneling spectroscopy, eventually in non-aqueous electrolytes which provide an increased double layer range available for voltage tunneling spectroscopy. Major impacts of the results of this project are expected in the fields of, e. g., nanoelectronics, catalysis, or nanoscale sensor applications.