1. Tunneling current modulation in atomically precise graphene nanoribbon heterojunctions
- Author
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Yannic Falke, Alexander Grüneis, Taichi Okuda, Boris V. Senkovskiy, Alexey V. Nenashev, Seyed Khalil Alavi, Martin Hell, Kenya Shimada, Felix R. Fischer, D. V. Rybkovskiy, Masashi Arita, Dmitry Yu. Usachov, Pantelis Bampoulis, Florian Gebhard, Thomas Szkopek, S. D. Baranovskii, Dirk Hertel, Alexander I. Chernov, Alexander Fedorov, Thomas Michely, Klaus Meerholz, Klas Lindfors, and Koji Miyamoto
- Subjects
Electronic properties and materials ,Materials science ,Science ,General Physics and Astronomy ,Large scale facilities for research with photons neutrons and ions ,02 engineering and technology ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,law.invention ,symbols.namesake ,Surfaces, interfaces and thin films ,law ,0103 physical sciences ,Monolayer ,Electronic devices ,010306 general physics ,Quantum tunnelling ,Molecular self-assembly ,Multidisciplinary ,Sensors ,business.industry ,Graphene ,Heterojunction ,General Chemistry ,021001 nanoscience & nanotechnology ,Modulation ,symbols ,Optoelectronics ,Scanning tunneling microscope ,0210 nano-technology ,business ,Raman spectroscopy ,Graphene nanoribbons - Abstract
Lateral heterojunctions of atomically precise graphene nanoribbons (GNRs) hold promise for applications in nanotechnology, yet their charge transport and most of the spectroscopic properties have not been investigated. Here, we synthesize a monolayer of multiple aligned heterojunctions consisting of quasi-metallic and wide-bandgap GNRs, and report characterization by scanning tunneling microscopy, angle-resolved photoemission, Raman spectroscopy, and charge transport. Comprehensive transport measurements as a function of bias and gate voltages, channel length, and temperature reveal that charge transport is dictated by tunneling through the potential barriers formed by wide-bandgap GNR segments. The current-voltage characteristics are in agreement with calculations of tunneling conductance through asymmetric barriers. We fabricate a GNR heterojunctions based sensor and demonstrate greatly improved sensitivity to adsorbates compared to graphene based sensors. This is achieved via modulation of the GNR heterojunction tunneling barriers by adsorbates., Here, the authors characterize the spectroscopic and transport properties of heterojunctions composed of quasi-metallic and semiconducting graphene nanoribbons (GNRs) with different widths, showing a predominant quantum tunnelling mechanism. The GNR heterojunctions can also be used to realize adsorbate sensors with high sensitivity.
- Published
- 2021