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Maniš J, Mach J, Bartošík M, Šamořil T, Horák M, Čalkovský V, Nezval D, Kachtik L, Konečný M, Šikola T. Low temperature 2D GaN growth on Si(111) 7 × 7 assisted by hyperthermal nitrogen ions. NANOSCALE ADVANCES 2022; 4:3549-3556. [PMID: 36134341 PMCID: PMC9400513 DOI: 10.1039/d2na00175f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 07/15/2022] [Indexed: 06/16/2023]
Abstract
As the characteristic dimensions of modern top-down devices are getting smaller, such devices reach their operational limits imposed by quantum mechanics. Thus, two-dimensional (2D) structures appear to be one of the best solutions to meet the ultimate challenges of modern optoelectronic and spintronic applications. The representative of III-V semiconductors, gallium nitride (GaN), is a great candidate for UV and high-power applications at a nanoscale level. We propose a new way of fabrication of 2D GaN on the Si(111) 7 × 7 surface using post-nitridation of Ga droplets by hyperthermal (E = 50 eV) nitrogen ions at low substrate temperatures (T < 220 °C). The deposition of Ga droplets and their post-nitridation are carried out using an effusion cell and a special atom/ion beam source developed by our group, respectively. This low-temperature droplet epitaxy (LTDE) approach provides well-defined ultra-high vacuum growth conditions during the whole fabrication process resulting in unique 2D GaN nanostructures. A sharp interface between the GaN nanostructures and the silicon substrate together with a suitable elemental composition of nanostructures was confirmed by TEM. In addition, SEM, X-ray photoelectron spectroscopy (XPS), AFM and Auger microanalysis were successful in enabling a detailed characterization of the fabricated GaN nanostructures.
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Affiliation(s)
- Jaroslav Maniš
- CEITEC BUT, Brno University of Technology Technická 3058/10 616 00 Brno Czech Republic
- Institute of Physical Engineering, Brno University of Technology Technická 2 616 69 Brno Czech Republic
| | - Jindřich Mach
- CEITEC BUT, Brno University of Technology Technická 3058/10 616 00 Brno Czech Republic
- Institute of Physical Engineering, Brno University of Technology Technická 2 616 69 Brno Czech Republic
| | - Miroslav Bartošík
- CEITEC BUT, Brno University of Technology Technická 3058/10 616 00 Brno Czech Republic
- Institute of Physical Engineering, Brno University of Technology Technická 2 616 69 Brno Czech Republic
- Department of Physics and Materials Engineering, Faculty of Technology, Tomas Bata University in Zlín Vavrečkova 275 760 01 Czech Republic
| | - Tomáš Šamořil
- Institute of Physical Engineering, Brno University of Technology Technická 2 616 69 Brno Czech Republic
| | - Michal Horák
- Institute of Physical Engineering, Brno University of Technology Technická 2 616 69 Brno Czech Republic
| | - Vojtěch Čalkovský
- Institute of Physical Engineering, Brno University of Technology Technická 2 616 69 Brno Czech Republic
| | - David Nezval
- Institute of Physical Engineering, Brno University of Technology Technická 2 616 69 Brno Czech Republic
| | - Lukáš Kachtik
- CEITEC BUT, Brno University of Technology Technická 3058/10 616 00 Brno Czech Republic
| | - Martin Konečný
- CEITEC BUT, Brno University of Technology Technická 3058/10 616 00 Brno Czech Republic
- Institute of Physical Engineering, Brno University of Technology Technická 2 616 69 Brno Czech Republic
| | - Tomáš Šikola
- CEITEC BUT, Brno University of Technology Technická 3058/10 616 00 Brno Czech Republic
- Institute of Physical Engineering, Brno University of Technology Technická 2 616 69 Brno Czech Republic
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Bartošík M, Mach J, Piastek J, Nezval D, Konečný M, Švarc V, Ensslin K, Šikola T. Mechanism and Suppression of Physisorbed-Water-Caused Hysteresis in Graphene FET Sensors. ACS Sens 2020; 5:2940-2949. [PMID: 32872770 DOI: 10.1021/acssensors.0c01441] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hysteresis is a problem in field-effect transistors (FETs) often caused by defects and charge traps inside a gate isolating (e.g., SiO2) layer. This work shows that graphene-based FETs also exhibit hysteresis due to water physisorbed on top of graphene determined by the relative humidity level, which naturally happens in biosensors and ambient operating sensors. The hysteresis effect is explained by trapping of electrons by physisorbed water, and it is shown that this hysteresis can be suppressed using short pulses of alternating gate voltages.
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Affiliation(s)
- Miroslav Bartošík
- Central European Institute of Technology - Brno University of Technology (CEITEC BUT), Purkyňova 123, 612 00 Brno, Czech Republic
- Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69 Brno, Czech Republic
- Department of Physics and Materials Engineering, Faculty of Technology, Tomas Bata University in Zlín, Vavrečkova 275, 760 01 Zlín, Czech Republic
| | - Jindřich Mach
- Central European Institute of Technology - Brno University of Technology (CEITEC BUT), Purkyňova 123, 612 00 Brno, Czech Republic
- Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69 Brno, Czech Republic
| | - Jakub Piastek
- Central European Institute of Technology - Brno University of Technology (CEITEC BUT), Purkyňova 123, 612 00 Brno, Czech Republic
- Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69 Brno, Czech Republic
| | - David Nezval
- Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69 Brno, Czech Republic
| | - Martin Konečný
- Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69 Brno, Czech Republic
| | - Vojtěch Švarc
- Central European Institute of Technology - Brno University of Technology (CEITEC BUT), Purkyňova 123, 612 00 Brno, Czech Republic
- Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69 Brno, Czech Republic
| | - Klaus Ensslin
- Solid State Physics Laboratory, ETH Zürich, CH 8093 Zürich, Switzerland
| | - Tomáš Šikola
- Central European Institute of Technology - Brno University of Technology (CEITEC BUT), Purkyňova 123, 612 00 Brno, Czech Republic
- Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69 Brno, Czech Republic
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