Nanochemistry under the ultimate spatial control of the plasmonic electric field

2015 Fiscal Year Final Research Report

• Project/Area Number: 25410003
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Physical chemistry
• Research Institution: Tohoku University
• Principal Investigator: Katano Satoshi 東北大学, 電気通信研究所, 准教授 (00373291)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 走査トンネル顕微鏡 / 金属ナノ微粒子 / 走査トンネル顕微鏡発光 / 局在表面プラズモン

Outline of Final Research Achievements

The strong enhancement of the electric field associated with local surface plasmon (LSP) excited on noble metal nanoparticles (NPs) plays a key role in various applications. The enhancement of the electric field is sensitive to the size and separation distance of NPs. Thus, these geometric parameters should be controlled precisely in order to utilize NPs as nano-scale optical devices. In this work, optical properties of single and assembled structures of AgNPs on Si(111) are studied using STM-LE spectroscopy. We found that the AgNP was created beneath the Ag tip by applying the negative voltage. The STM-LE spectrum of AgNP exhibits a broad peak in the visible light range. Size dependent study indicated that the peak intensity is increased with increasing the AgNP size, accompanying the shift of the peak position. Furthermore, the shape-dependent optical behavior of a single AgNP has been clarified using STM-LE, which is well reproduced by the theoretical calculation.

Free Research Field

表面物理化学