金属和半导体协同贡献的表面增强拉曼散射研究

In this project, the traditional noble metal SERS-active substrate (Ag, Au etc.) and novel semiconductor SERS-active substrate will be intentionally combined into the composite system for developing new style high SERS-active substrate with their synergistic contribution to SERS effect. And SERS effect from synergistic contribution of metal and semiconductor and its enhanced mechanism will be investigated in detail. A series of assemblies with probe molecules, semiconductor (TiO2, ZnO, ZnS, ZrO2 etc.) and/or noble metal (Ag, Au etc.) nanoparticles (NPs) will be fabricated by a self-assembly method, in which semiconductor and noble metal NPs have to be chosen reasonably based on the consideration of some factors such as the electron configuration (band structure, surface defect) of semiconductor nanometer materials, the electronegativity of noble metal, particle size, particle shape as well as the polarity of probe molecule. The behaviors about interface charge transfer and mutual interaction between the noble metal and the semiconductor as well as probe molecules and different active substrates are going to be discussed mostly for revealing the contributing factors of SERS effect from synergistic contribution of metal and semiconductor, and deeply understanding existential internal relations among these contributing factors. And based on above investigations, the internal relations between the photophysics and the photochemistry properties of semiconductor nanometer materials and metal/semiconductor nanometer composite materials also will be probed. The means and methods that can reveal surface and interface properties of semiconductor nanometer materials and metal/semiconductor nanometer composite materials by SRES technology will be established. It is expected that the present work would be valuable and significance for not only the development of SERS theory but also practical application of SERS technology in materials field.

本项目将传统的SERS活性基底（Au、Ag等贵金属）与新型的半导体纳米材料SERS活性基底进行有机结合，构筑二者协同贡献的新型高SERS活性基底，开展金属和半导体协同贡献的表面增强拉曼散射及其增强机制研究。选择适当的半导体和贵金属纳米材料，通过改变半导体纳米材料的电子组态（能带结构）、金属电负性、探针分子极性、粒子尺寸（或形状）等因素，构筑具有协同SERS效应的组装体，探讨金属和半导体之间以及探针分子和基底之间的界面电荷转移行为及相互作用行为，揭示金属和半导体协同SERS效应的贡献和影响因素以及它们之间存在的内在关系。并且，在上述基础上探讨半导体纳米材料和金属/半导体纳米复合材料的光物理和光化学性能之间的内在关系，建立用SERS技术揭示半导体及金属/半导体复合材料表界面性质的手段和方法。此研究无论是对SERS理论的发展还是对SERS技术在材料领域的实际应用都具有重要的意义。

基于半导体的SERS研究无论是在SERS领域还是在材料领域都显示出了广阔的应用前景，具有重要的理论和实际意义。本项目将传统的贵金属SERS活性基底与新型的半导体SERS活性基底进行有机结合，在贵金属和半导体SERS基底的研究基础上，构建二者协同贡献的新型高SERS活性基底。揭示金属和半导体协同贡献的SERS增强机制，探讨金属和半导体之间以及分子和基底之间的界面电荷转移行为及相互作用行为，揭示半导体纳米材料的带隙结构（包括缺陷能级）、金属电负性、探针分子极性等因素对协同SERS效应的贡献和影响以及它们之间存在的内在关系（协同效应），建立用SERS技术揭示半导体及金属/半导体复合材料表界面性质的手段和方法。此项目研究对于SERS理论的发展以及SERS技术在材料领域的实际应用具有重要的意义。