Fabrication of Metallic Architectures for precise control of energy conversion

点击翻译按钮获取中文摘要

In this project, we have fabricated structurally well-defined metallic nano-architectures that are capable of energy conversion among thermal, photon, kinetic, and electro-chemical energies. Especially, we have concentrated three subjects below. First is a controlling of an electron conduction process in a metal atomic wire. In the atomic wire connected by a single atom junction, electron conduction characteristics can be controlled by external electro-chemical energy. We have succeeded in controlling of energy-and spin-selective electron conduction based on the electro-chemical potential at both electrode of the junction. Additionally, an in-situ measurement of vibrational spectrum has clarified the insertion process of a small molecule in the junction. Second is a conversion of photon energy to molecular vibration energy. To realize an effective conversion, we focused locally enhanced electric field around metal nano-architecture. Electrons in the architecture collectively oscillate by a light-irradiation with resonant energy. This causes highly enhanced electric field around the architecture. By measuring a Raman scattering signal from a single molecule situating at a close proximity of the architecture, we have found that the scattering cross-section was increased by the order of 10^10 compared with normal Raman process. Third is a controlling a molecular diffusion energy by using of metallic architecture. Two-dimensional array of metallic nano-architecture has demonstrated rectification ability concerning a collective flow of a molecular assembly. These research results in the present project will offers new molecular/electron manipulation, rectification, and detection systems in a future nano-devices.