Achieving Molecular Level Control over the Chemical, Electrochemical, and Electrical Properties of Crystalline Si Surfaces

在化学部分析和表面化学项目的支持下，加州理工学院的Nathan S. Lewis教授和他的同事们正在研究晶体硅表面的表面化学。这项工作的重点是硅表面的湿化学处理，目标是开发在电化学环境中抑制硅氧化的方法，控制硅表面上介电层和阻挡层的形成，并以受控的几何形状将氧化还原活性基团附着在表面上。研究人员还在探索纳米级材料层在改性硅表面的附着和形成。这项工作建立在首席研究员实验室开发的卤化/烷基化化学基础上，将影响硅在太阳能电池应用中的使用，对界面电子转移的基本理解，以及硅基传感器设备的开发。该研究在电镀控制和电催化等领域的应用前景十分广阔。晶体硅表面化学的控制是本研究项目的目标，该项目得到了分析和表面化学计划的支持。采用基于硅表面卤化和后续烷基化的湿化学处理方法对硅表面进行钝化和改性，并在硅表面上可控地沉积纳米级颗粒。这项工作将影响表面化学和分析化学的广泛领域，包括传感器设备的发展、太阳能的转换和半导体表面的金属涂层。

With the support of the Analytical and Surface Chemistry Program of the Chemistry Division, Professor Nathan S. Lewis and his coworkers at the California Institute of Technology are investigating the surface chemistry of crystalline silicon surfaces. The emphasis in this work is on the wet chemical processing of silicon surfaces, with the goal of developing methods to suppress oxidation of silicon in the electrochemical environment, to control the formation of dielectric and barrier layers on the silicon surface, and to attach redox active groups to the surface in controlled geometries. Work is also underway to explore the attachment and formation of patterned layers of nanoscale materials to the modified silicon surface. The work builds on halogenation/alkylation chemistry developed in the Principal Investigator's laboratory and will impact the use of silicon in solar cell applications, the basic understanding of electron transfer at interfaces, and the development of silicon based-sensor devices. Applications of this work to controlled electroplating and electrocatalysis are also expected. The control of the surface chemistry of crystalline silicon surfaces is the goal of this research project supported in the Analytical and Surface Chemistry Program. Wet chemical processing methods based on halogenation and subsequent alkylation of the silicon surface are used to passivate and modify the silicon surface, and to controllably deposit nanometer sized particles on the silicon surface. This work will impact broad areas of surface and analytical chemistry, including the development of sensor devices, the conversion of solar energy, and the metallic coating of semiconductor surfaces.