用于纳米劈裂技术的新型芯片及增强拉曼光谱实验

为了定量研究纳米颗粒的间距对拉曼(Raman)光谱强度的影响,研制了具有高稳定性的纳米劈裂芯片及装置。利用此芯片及装置,可以获得纳米金属桥断裂后自动形成的两针状纳米电极(纳米颗粒),并且能在pm级精度上操纵两纳米电极间的距离,以观察相应拉曼光谱强度的变化。在利用两纳米电极作为增强体的基础上引入了第3纳米电极,以观察其位置对拉曼光谱信号的影响。实验结果表明,光谱信号的强度强烈依赖于3纳米电极的相对位置,第3纳米电极的引入能进一步提高增强因子,为拉曼光谱增强机制的理论研究提供了重要参考数据。

Preparation of novel chips for mechanical controllable break junctions and experiment of enhanced Raman spectroscopy

In order to better understand the enhanced Raman signal dependence on the separation between two nanoparticles,a chip for the mechanical controllable break junctions as well as high stability setup was fabricated.With such a device,two sharply tip-shape nanoelectrodes were obtained automatically after the breaking of the nano metal wire,and the gap size between the two nanoelectrodes can be adjusted in pico-meter accuracy during the Raman spectroscopy measurement.Furthermore,the third electrode was introduced based on the two tip enhanced Raman scattering.The effect of the electrode position on the Raman signal intensity was investigated.The experiment results demonstrate that the signal intensity is strongly dependent on the alignment of three nanoelectrodes,and the introduced third electrode can enhance the Raman signal further,supplying the theory investigation for the enhanced mechanism.