Thiophene-based Tripodal Anchor Units for Hole Transport in Single-Molecule Junctions with Gold Electrodes

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• 作者：Yutaka Ie ; Kazunari Tanaka ; Aya Tashiro ; See Kei Lee ; Henrique Rosa Testai ; Ryo Yamada ; Hirokazu Tada ; Yoshio Aso
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2015
• 出版时间：September 17, 2015
• 年：2015
• 卷：6
• 期：18
• 页码：3754-3759
• 全文大小：361K
• ISSN：1948-7185

文摘

Molecule鈥搈etal junctions are inevitable for the realization of single-molecule electronics. In this study, we developed new tripodal anchors with electron-rich aromatic rings to achieve robust contact with gold electrodes, an effective hybridization of the 蟺 orbital with gold electrodes (蟺 channel), and hole transport through 蟺-channel hybridization. Cyclic voltammetry and X-ray photoelectron spectroscopy measurements of the monolayers indicated that the thiophene-based tripodal molecule exhibits anchoring characteristics as expected. The electrical conductance of thiophene-anchored bistripodal molecules using the scanning tunneling microscope (STM)-based break junction technique confirmed the formation of molecular junctions. The Seebeck coefficient of this compound estimated from thermoelectric voltage measurements using a STM was determined to be a positive value, which indicates that the charge carriers are holes. On the contrary, the corresponding pyridine-anchored molecules showed electron transport. These results reveal the versatility of 蟺-channel tripodal anchors for the control of charge-carrier type in single-molecule electronics.