Band gap engineering in two-dimensional materials by functionalization
- Graphene is well-knownfor its unique combination of electricaland mechanical properties. However, its vanishing band gap limitsthe use of graphene in microelectronics. Covalent functionalizationof graphene has been a common approach to address this critical issueand introduce a band gap. In this Article, we systematically analyzethe functionalization of single-layer graphene (SLG) and bilayer graphene(BLG) with methyl (CH3) using periodic density functionaltheory (DFT) at the PBE+D3 level of theory. We also include a comparisonof methylated single-layer and bilayer graphene, as well as a discussionof different methylation options (radicalic, cationic, and anionic).For SLG, methyl coverages ranging from 1/8 to 1/1, (i.e.,the fully methylated analogue of graphane) are considered. We findthat up to a coverage theta of 1/2, graphene readily accepts CH3, with neighbor CH3 groups preferring trans positions. Above theta = 1/2, the tendency to accept further CH3 weakens and the lattice constant increases. The band gapbehaves less regularly,Graphene is well-knownfor its unique combination of electricaland mechanical properties. However, its vanishing band gap limitsthe use of graphene in microelectronics. Covalent functionalizationof graphene has been a common approach to address this critical issueand introduce a band gap. In this Article, we systematically analyzethe functionalization of single-layer graphene (SLG) and bilayer graphene(BLG) with methyl (CH3) using periodic density functionaltheory (DFT) at the PBE+D3 level of theory. We also include a comparisonof methylated single-layer and bilayer graphene, as well as a discussionof different methylation options (radicalic, cationic, and anionic).For SLG, methyl coverages ranging from 1/8 to 1/1, (i.e.,the fully methylated analogue of graphane) are considered. We findthat up to a coverage theta of 1/2, graphene readily accepts CH3, with neighbor CH3 groups preferring trans positions. Above theta = 1/2, the tendency to accept further CH3 weakens and the lattice constant increases. The band gapbehaves less regularly, but overall it increases with increasing methylcoverage. Thus, methylated graphene shows potential for developingband gap-tuned microelectronics devices and may offer further functionalizationoptions. To guide in the interpretation of methylation experiments,vibrational signatures of various species are characterized by normal-modeanalysis (NMA), their vibrational density of states (VDOS), and infrared(IR) spectra, the latter two are obtained from ab initio moleculardynamics (AIMD) in combination with a velocity-velocity autocorrelationfunction (VVAF) approach.…
Verfasserangaben: | Elham MazareiORCiD, Christopher PenschkeORCiDGND, Peter SaalfrankORCiDGND |
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DOI: | https://doi.org/10.1021/acsomega.3c02068 |
ISSN: | 2470-1343 |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/37360460 |
Titel des übergeordneten Werks (Englisch): | ACS Omega |
Untertitel (Englisch): | Methylation of graphene and graphene bilayers |
Verlag: | American Chemical Society |
Verlagsort: | Washington |
Publikationstyp: | Wissenschaftlicher Artikel |
Sprache: | Englisch |
Datum der Erstveröffentlichung: | 05.07.2023 |
Erscheinungsjahr: | 2023 |
Datum der Freischaltung: | 20.06.2024 |
Freies Schlagwort / Tag: | Adsorption; Alkyls; Band structure; Electrical conductivity; Two dimensional materials |
Band: | 8 |
Ausgabe: | 24 |
Seitenanzahl: | 16 |
Erste Seite: | 22026 |
Letzte Seite: | 22041 |
Fördernde Institution: | Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under; Germany's Excellence Strategy [EXC 2008/1-390540038, Sa 548/18-1,; 491466077] |
Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
DDC-Klassifikation: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
6 Technik, Medizin, angewandte Wissenschaften / 66 Chemische Verfahrenstechnik / 660 Chemische Verfahrenstechnik | |
Peer Review: | Referiert |
Fördermittelquelle: | Publikationsfonds der Universität Potsdam |
Publikationsweg: | Open Access / Gold Open-Access |
DOAJ gelistet | |
Lizenz (Deutsch): | CC-BY-NC-ND - Namensnennung, nicht kommerziell, keine Bearbeitungen 4.0 International |