Understanding the optical properties of doped and undoped 9-armchair graphene nanoribbons in dispersion
Graphene nanoribbons are one-dimensional stripes of graphene with width- and edge-structure-dependent electronic properties. They can be synthesized bottom-up in solution to obtain precise ribbon geometries. Here we investigate the optical properties of solution-synthesized 9-armchair graphene nanor...
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| Main Authors: | , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
September 26, 2023
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| In: |
ACS nano
Year: 2023, Volume: 17, Issue: 18, Pages: 18240-18252 |
| ISSN: | 1936-086X |
| DOI: | 10.1021/acsnano.3c05246 |
| Online Access: | Verlag, kostenfrei, Volltext: https://doi.org/10.1021/acsnano.3c05246
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| Author Notes: | Sebastian Lindenthal, Daniele Fazzi, Nicolas F. Zorn, Abdurrahman Ali El Yumin, Simon Settele, Britta Weidinger, Eva Blasco, and Jana Zaumseil |
| Summary: | Graphene nanoribbons are one-dimensional stripes of graphene with width- and edge-structure-dependent electronic properties. They can be synthesized bottom-up in solution to obtain precise ribbon geometries. Here we investigate the optical properties of solution-synthesized 9-armchair graphene nanoribbons (9-aGNRs) that are stabilized as dispersions in organic solvents and further fractionated by liquid cascade centrifugation (LCC). Absorption and photoluminescence spectroscopy reveal two near-infrared absorption and emission peaks whose ratios depend on the LCC fraction. Low-temperature single-nanoribbon photoluminescence spectra suggest the presence of two different nanoribbon species. Based on density functional theory (DFT) and time-dependent DFT calculations, the lowest energy transition can be assigned to pristine 9-aGNRs, while 9-aGNRs with edge-defects, caused by incomplete graphitization, result in more blue-shifted transitions and higher Raman D/G-mode ratios. Hole doping of 9-aGNR dispersions with the electron acceptor F4TCNQ leads to concentration dependent bleaching and quenching of the main absorption and emission bands and the appearance of red-shifted, charge-induced absorption features but no additional emission peaks, thus indicating the formation of polarons instead of the predicted trions (charged excitons) in doped 9-aGNRs. |
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| Item Description: | Online veröffentlicht: 11. September 2023 Gesehen am 25.10.2023 |
| Physical Description: | Online Resource |
| ISSN: | 1936-086X |
| DOI: | 10.1021/acsnano.3c05246 |