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Smooth gap tuning strategy for cove-type graphene nanoribbons
Tiago de Sousa Araújo Cassiano1, Fábio Ferreira Monteiro1, Leonardo Evaristo de Sousa2
1Institute of Physics, University of Brasília Brazil pedrohenrique@unb.br.
RSC Advances
|May 6, 2022
Summary
Researchers tuned the energy bandgap of graphene nanoribbons (GNRs) by modifying their edges. This method allows for precise control over GNRs, making them suitable for optoelectronic applications.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Graphene, a carbon allotrope, possesses remarkable properties but lacks a bandgap, limiting its use in optoelectronics.
- Graphene nanoribbons (GNRs) can exhibit a bandgap, enabling optoelectronic applications.
- Cove-type GNRs offer a pathway for large-scale production with a reported bandgap of 1.88 eV.
Purpose of the Study:
- To develop an edge termination strategy for smoothly tuning the energy bandgap of cove-type GNRs.
- To investigate the relationship between edge structure periodicity and bandgap modulation.
- To compare the impact of edge termination on lattice deformation with changes in nanoribbon width.
Main Methods:
- Utilized an extended two-dimensional Su-Schrieffer-Heeger tight-binding model.
- Systematically varied the periodicity of alternating armchair-like and zigzag-like edges.
- Analyzed lattice deformation and morphological changes due to edge modifications.
Main Results:
- Successfully demonstrated smooth tuning of the energy bandgap in cove-type GNRs.
- Achieved bandgap values ranging from approximately 3 eV down to nearly 0 eV.
- Observed a trade-off between bandgap reduction and decreased conjugation/increased morphological spreading.
Conclusions:
- The proposed edge termination strategy offers a flexible method for controlling the electronic properties of cove-type GNRs.
- This tunability makes cove-type GNRs a promising material for diverse optoelectronic applications.
- Further research can explore optimizing edge structures for specific optoelectronic device requirements.
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