Electromechanical Properties of Single-Molecule Junctions

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05245
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 28010:Nanometer-scale chemistry-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Fujii Shintaro 東京工業大学, 理学院, 特任准教授 (70422558)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 単分子接合 / ブレイクジャンクション / 電気伝導度 / 熱起電力

Outline of Final Research Achievements

Single-molecule junctions have attracted attention for their application as single-molecule devices and as model systems for metal-molecule interfaces in organic electronic devices. In single-molecule junctions, the interface structure and molecular conformation change reversibly, and the properties such as electrical transport and thermoelectric properties exhibit tunable mechanical response. In this study, we investigate the mechanical modulation of thermoelectric properties of single-molecule junctions by mechanically changing the molecular orientation and the structure of the molecule-metal interface. We confirmed that the thermopower of single-molecule junctions can be increased or decreased by applying mechanical external forces. Theoretical simulations revealed that the t thermopower modulates in response to mechanically induced changes in the metal-molecule interface structure and molecular orbital energy.

Free Research Field

表面科学

Academic Significance and Societal Importance of the Research Achievements

単分子接合の物性の力学的応答性に着目し、従来の孤立分子や結晶では発現しない、または隠れていた物性の解明を行った。単分子接合ではナノメートルスケールの微小な電極変位に起因する外力に対し、熱電能が応答性を示すことを見出した。本研究は、将来の分子エレクトロニクス実装に必要な、熱電特性を制御する新たな力学的なアプローチのひとつを提供するものである。