Colóquio Extra 17/10/2023: Bottom-up fabrication of graphene nanoribbons: from ultra-high-vacuum

Graphene nanoribbons (GNRs) show exciting properties deriving from electron confinement and related band gap tunability¹. The ability to tune GNRs’ electronic and magnetic properties at the single atom level makes them an ideal platform for a wide range of device applications, from classical transistors to spintronics. In this talk, I will give an overview of the necessary steps to bring GNRs from ultra-high vacuum (UHV) to device integration focusing on the synthesis, characterization and transport measurements of atomically-precise graphene nanoribbons. After the UHV bottom-up growth, GNRs are transferred using different transfer methods based on wet-processes such as polymer-free² and/or an electrochemical delamination method³, as well as semi-dry/dry-transfer methods. Those processes allow the characterization of GNRs fingerprint modes via Raman spectroscopy^3,4 as well as the characterization of their electronic properties on decoupled substrates such as quasi-free-standing graphene. Next, I will show our progress on integrating different armchair GNRs (5-, 9-, 17-AGNRs)^5,6 into field-effect transistors with different gate and contact configurations. As a brief overview, we recently demonstrated the highest Ion current GNR-FET device to date by using a double-gate configuration⁷. 9-AGNR-FETs showed Ion currents up to 12μA and Ion/Ioff up to 10⁵. By integrating 9-AGNRs into FET devices using graphene⁸ and carbon nanotubes⁹ as electrodes we also demonstrated tunable multi-gate devices showing quantum dot behavior with rich Coulomb diamond patterns.

1. J. Cai et al., Nature, 466, 2010
2. G. Borin Barin et al., ACS Applied Nanomaterials, 2, 2019
3. Overbeck & Borin Barin et al., Pssb, 12, 2019
4. Overbeck & Borin Barin et al., ACS Nano, 19, 2019
5. Llinas et al., Nature Communications, 8, 2017
6. Borin Barin et al., Small, 18, 2022
7. Mutlu et al., IEEE International Electron Devices Meeting (IEDM), 37.4. 1-37.4. 4, 2021
8. Jian Zhang et al., Advanced Electronic Materials, 2201204, 2023
9. Jian Zhang et al., Nature Electronics, 2023

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Sobre a palestrante

Gabriela Borin Barin received her Ph.D. in Materials Science and Engineering in 2014 from the Federal University of Sergipe (Brazil). Her Ph.D was carried out in a joint project between Federal University of Sergipe and the Massachusetts Institute of Technology (MIT) in which she studied parameters optimization for preparation of monolayer graphene and graphite/graphene-like structures under the guidance of Prof. Jing Kong. She joined the nanotech@surfaces laboratory at Empa in 2015, her research focus is set on the synthesis and transfer of graphene nanoribbons for ex situ characterization and device application. Gabriela has a strong background in experimental chemistry and materials science, especially in transfer and characterization of graphene and graphene related materials, acquired since her Bachelor in Chemistry and Master in Materials Science and Engineering, both carried out under Prof. Ledjane Barreto’s guidance at the Federal University of Sergipe (Brazil). Her technical skills cover a broad range of characterization techniques such as scanning probe microscopies (STM, AFM), Thermal Analysis (TG/DSC), X-ray Diffraction (XRD), Electron Microscopies (SEM, TEM) and Raman, Infrared and UV-Vis spectroscopies.
Gabriela has obtained several Research Fellowships including a Scholarship from CAPES Foundation (Brazilian Federal Agency for Support and Evaluation of Graduate Education) to carry out her doctoral project at the Massachusetts Institute of Technology (MIT) and a Marie-Curie Cofund Scholarship for the Empa Post-Doctoral Program (2015-2016). Gabriela participated in several international conferences with oral and poster contributions and published various articles in peer reviewed journals.

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Para assistir remotamente via Zoom,
https://us06web.zoom.us/j/89575113960?pwd=aQENjY4pj5zGZCwH2JT6bfEDBbk4cu.1

ID da reunião: 895 7511 3960
Senha: 416406

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