To optical properties of carbon nanoparticles: A need in comprehending Urbach energy
In this work, light absorption spectra of carbon nanoparticles sampled at different heights from an ethylene/air premixed flame were studied. The spectral behavior of the light absorption coefficient was analyzed in the high energy (Tauc) and low energy (Urbach) regions. In the Tauc region, informat...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-07-01
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| Series: | Carbon Trends |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2667056922000402 |
| _version_ | 1811225848553930752 |
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| author | Francesca Migliorini Silvia Belmuso Roberto Dondè Silvana De Iuliis Igor Altman |
| author_facet | Francesca Migliorini Silvia Belmuso Roberto Dondè Silvana De Iuliis Igor Altman |
| author_sort | Francesca Migliorini |
| collection | DOAJ |
| description | In this work, light absorption spectra of carbon nanoparticles sampled at different heights from an ethylene/air premixed flame were studied. The spectral behavior of the light absorption coefficient was analyzed in the high energy (Tauc) and low energy (Urbach) regions. In the Tauc region, information on the optical band gap can be retrieved, while in the Urbach region the value of the Urbach energy can be estimated. The variation of the spectral behavior of the light absorption coefficient in the low energy region was ascribed to different Urbach energies of the material depending on the sampling height. The Urbach energy is related to the disorder of the particles under analysis. The conclusion was made that due to the strong tail absorption, the traditional optical band gap concept is not an accurate approach in describing properties of studied nanocarbons, which can be better emphasized with the Urbach parameter. Moreover, the high value of the Urbach energy obtained is hypothesized to occur due to the fast nanoparticle formation in a flame that leads to a strong structural disorder. A thorough study of the Urbach energy and its relation to the nanoparticle growth looks an essential step in comprehending optical properties of carbonaceous particulate generated in flames. |
| first_indexed | 2024-04-12T09:14:06Z |
| format | Article |
| id | doaj.art-b4b55cced6dc45b9b695a48a03f41055 |
| institution | Directory Open Access Journal |
| issn | 2667-0569 |
| language | English |
| last_indexed | 2024-04-12T09:14:06Z |
| publishDate | 2022-07-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Carbon Trends |
| spelling | doaj.art-b4b55cced6dc45b9b695a48a03f410552022-12-22T03:38:53ZengElsevierCarbon Trends2667-05692022-07-018100184To optical properties of carbon nanoparticles: A need in comprehending Urbach energyFrancesca Migliorini0Silvia Belmuso1Roberto Dondè2Silvana De Iuliis3Igor Altman4CNR-ICMATE, Institute of Condensed Matter Chemistry and Technologies for Energy, via R. Cozzi 53, 20125 Milan, ItalyCNR-STEMS, Institute of Sciences and Technologies for Sustainable Energy and Mobility, Piazzale Tecchio 80, Naples 80125, ItalyCNR-ICMATE, Institute of Condensed Matter Chemistry and Technologies for Energy, via R. Cozzi 53, 20125 Milan, ItalyCNR-ICMATE, Institute of Condensed Matter Chemistry and Technologies for Energy, via R. Cozzi 53, 20125 Milan, Italy; Corresponding authors.Combustion Sciences and Propulsion Research Branch, Naval Air Warfare Center Weapons Division, 1 Administration Circle, China Lake, CA 93555, USA; Corresponding authors.In this work, light absorption spectra of carbon nanoparticles sampled at different heights from an ethylene/air premixed flame were studied. The spectral behavior of the light absorption coefficient was analyzed in the high energy (Tauc) and low energy (Urbach) regions. In the Tauc region, information on the optical band gap can be retrieved, while in the Urbach region the value of the Urbach energy can be estimated. The variation of the spectral behavior of the light absorption coefficient in the low energy region was ascribed to different Urbach energies of the material depending on the sampling height. The Urbach energy is related to the disorder of the particles under analysis. The conclusion was made that due to the strong tail absorption, the traditional optical band gap concept is not an accurate approach in describing properties of studied nanocarbons, which can be better emphasized with the Urbach parameter. Moreover, the high value of the Urbach energy obtained is hypothesized to occur due to the fast nanoparticle formation in a flame that leads to a strong structural disorder. A thorough study of the Urbach energy and its relation to the nanoparticle growth looks an essential step in comprehending optical properties of carbonaceous particulate generated in flames.http://www.sciencedirect.com/science/article/pii/S2667056922000402Carbon nanoparticlesLight absorptionAbsorption coefficientUrbach energy |
| spellingShingle | Francesca Migliorini Silvia Belmuso Roberto Dondè Silvana De Iuliis Igor Altman To optical properties of carbon nanoparticles: A need in comprehending Urbach energy Carbon Trends Carbon nanoparticles Light absorption Absorption coefficient Urbach energy |
| title | To optical properties of carbon nanoparticles: A need in comprehending Urbach energy |
| title_full | To optical properties of carbon nanoparticles: A need in comprehending Urbach energy |
| title_fullStr | To optical properties of carbon nanoparticles: A need in comprehending Urbach energy |
| title_full_unstemmed | To optical properties of carbon nanoparticles: A need in comprehending Urbach energy |
| title_short | To optical properties of carbon nanoparticles: A need in comprehending Urbach energy |
| title_sort | to optical properties of carbon nanoparticles a need in comprehending urbach energy |
| topic | Carbon nanoparticles Light absorption Absorption coefficient Urbach energy |
| url | http://www.sciencedirect.com/science/article/pii/S2667056922000402 |
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