Development and application of optical microspectroscopy with proton sensitivity and high spatial resolution

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H00865
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 29:Applied condensed matter physics and related fields
• Research Institution: Institute for Molecular Science
• Principal Investigator: Toshiki Sugimoto 分子科学研究所, 物質分子科学研究領域, 准教授 (00630782)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 極微分光法 / 顕微鏡 / レーザー分光法 / 非線形分光法 / 水素結合

Outline of Final Research Achievements

The local configuration of proton in hydrogen-bonding networks on solid surfaces is an essentially important structural information for the emergence of unique functions in water aggregation systems. However, it is difficult to elucidate the local structure of proton in surface hydrogen-bonding networks using existing surface science methods such as X-ray and electron beams. In this study, we focused on the development of a microspectroscopy system that combines scanning tunneling microscopy and nonlinear spectroscopy. In particular, the sophistication of the electrochemical etching process for metals has made it possible to control the tip shape of the plasmonic metal probe, which holds the key to nanoscale microspectroscopy, with high reproducibility on a nanoscale. As a result, we succeeded in highly sensitive measurement of STM emission induced at the tip of the probe and nonlinear spectroscopic signals directly under the probe.

Free Research Field

応用物理物性およびその関連分野(薄膜及び表面界面)

Academic Significance and Societal Importance of the Research Achievements

本研究では、金属ナノ探針の加工法と整形法の高度化に成功した。これにより、光の回折・集光限界よりも数桁も小さなナノスケールの極微空間にパルス光を閉じ込めることが高い再現性で可能となり、ナノキャビティにおける非線形分子分光計測の方向性を拓くことができた。特に、高い安定性を持つ金属ナノ探針を再現性よく作製するという技術革新により、ナノスケールの極微光と分子の相互作用や表面水素結合系の機能を微視的に探求する確固たる技術的・物理化学的基礎を構築することができた。これらの成果は、ナノフォトニクス分野・触媒表面化学分野の今後の飛躍的発展に貢献することが期待される。