Nanoscale photoelectronic properties of graphene oxide revealed by STM multi-spectroscopy

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K21114
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 28:Nano/micro science and related fields
• Research Institution: Toyo University (2022); Tohoku University (2020-2021)
• Principal Investigator: Katano Satoshi 東洋大学, 理工学部, 教授 (00373291)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: 酸化グラフェン / 走査トンネル顕微鏡 / 走査トンネル分光 / 走査トンネル顕微鏡発光

Outline of Final Research Achievements

The optoelectronic properties of graphene oxide (GO) are dominated by nanostructures composed of conductive domains that retain the graphene structure and insulating domains with attached oxygen functional groups. In particular, the size and spatial distribution of the conductive domains are major factors that determine the functionality of GO, such as electrical conduction and light emission. In this project, we conducted research to elucidate the nano-photoelectronic properties of GO by using of spectroscopy technology based on a scanning tunneling microscope (STM). In this research, we investigated the adsorption of single-layer GO onto the substrate and the control of the adsorption structure, the identification of the microscopic electronic states of the nanodomains contained in the GO sheet by STM and scanning tunneling spectroscopy (STS). We have made some progress on the identification of the light emission domain of GO.

Free Research Field

表面物理化学

Academic Significance and Societal Importance of the Research Achievements

次世代デバイス材料として有望なGOの物性は、これまでラマン分光や接触AFMなどで評価されてきた。しかし、これらの計測手法では、応用上極めて重要と考えられている数nmに局在したナノドメインを直接評価できない。本研究では、個々のナノドメインにアクセス可能なSTMを用いてGOの光電子物性を原子スケールで明らかにした。GOは、安価で大量合成が可能であり、さらに生体分子との融合性が高く応用研究への見通しがよい。GOの微視的理解は、微量で多種の生体分子の同時検出を可能にする高感度バイオセンサーの実現にもつながり、本研究の波及効果は基礎研究の枠に留まらないと考えられる。