Optical Gain in Semiconducting Polymer Nano and Mesoparticles
The presence of excited-states and charge-separated species was identified through UV and visible laser pump and visible/near-infrared probe femtosecond transient absorption spectroscopy in spin coated films of poly[<i>N</i>-9″-heptadecanyl-2,7-carbazole-<i>alt</i>-5,5-(4,7-d...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-02-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/26/4/1138 |
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| author | Mark Geoghegan Marta M. Mróz Chiara Botta Laurie Parrenin Cyril Brochon Eric Cloutet Eleni Pavlopoulou Georges Hadziioannou Tersilla Virgili |
| author_facet | Mark Geoghegan Marta M. Mróz Chiara Botta Laurie Parrenin Cyril Brochon Eric Cloutet Eleni Pavlopoulou Georges Hadziioannou Tersilla Virgili |
| author_sort | Mark Geoghegan |
| collection | DOAJ |
| description | The presence of excited-states and charge-separated species was identified through UV and visible laser pump and visible/near-infrared probe femtosecond transient absorption spectroscopy in spin coated films of poly[<i>N</i>-9″-heptadecanyl-2,7-carbazole-<i>alt</i>-5,5-(4,7-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT) nanoparticles and mesoparticles. Optical gain in the mesoparticle films is observed after excitation at both 400 and 610 nm. In the mesoparticle film, charge generation after UV excitation appears after around 50 ps, but little is observed after visible pump excitation. In the nanoparticle film, as for a uniform film of the pure polymer, charge formation was efficiently induced by UV excitation pump, while excitation of the low energetic absorption states (at 610 nm) induces in the nanoparticle film a large optical gain region reducing the charge formation efficiency. It is proposed that the different intermolecular interactions and molecular order within the nanoparticles and mesoparticles are responsible for their markedly different photophysical behavior. These results therefore demonstrate the possibility of a hitherto unexplored route to stimulated emission in a conjugated polymer that has relatively undemanding film preparation requirements. |
| first_indexed | 2024-03-09T00:41:11Z |
| format | Article |
| id | doaj.art-f98b3a3e47824ec9bb2f598653959b27 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-09T00:41:11Z |
| publishDate | 2021-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-f98b3a3e47824ec9bb2f598653959b272023-12-11T17:50:39ZengMDPI AGMolecules1420-30492021-02-01264113810.3390/molecules26041138Optical Gain in Semiconducting Polymer Nano and MesoparticlesMark Geoghegan0Marta M. Mróz1Chiara Botta2Laurie Parrenin3Cyril Brochon4Eric Cloutet5Eleni Pavlopoulou6Georges Hadziioannou7Tersilla Virgili8Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, UKIFN-CNR, Dipartimento di Fisica, Politecnico di Milano, 20132 Milan, ItalySCITEC-CNR, Istituto di Scienze e Tecnologie Chimiche “Giulio Natta”, 20133 Milan, ItalyLaboratoire de Chimie des Polymères Organiques (LCPO) UMR 5629, CNRS-Université de Bordeaux-Bordeaux INP, CEDEX, 33607 Pessac, FranceLaboratoire de Chimie des Polymères Organiques (LCPO) UMR 5629, CNRS-Université de Bordeaux-Bordeaux INP, CEDEX, 33607 Pessac, FranceLaboratoire de Chimie des Polymères Organiques (LCPO) UMR 5629, CNRS-Université de Bordeaux-Bordeaux INP, CEDEX, 33607 Pessac, FranceLaboratoire de Chimie des Polymères Organiques (LCPO) UMR 5629, CNRS-Université de Bordeaux-Bordeaux INP, CEDEX, 33607 Pessac, FranceLaboratoire de Chimie des Polymères Organiques (LCPO) UMR 5629, CNRS-Université de Bordeaux-Bordeaux INP, CEDEX, 33607 Pessac, FranceIFN-CNR, Dipartimento di Fisica, Politecnico di Milano, 20132 Milan, ItalyThe presence of excited-states and charge-separated species was identified through UV and visible laser pump and visible/near-infrared probe femtosecond transient absorption spectroscopy in spin coated films of poly[<i>N</i>-9″-heptadecanyl-2,7-carbazole-<i>alt</i>-5,5-(4,7-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT) nanoparticles and mesoparticles. Optical gain in the mesoparticle films is observed after excitation at both 400 and 610 nm. In the mesoparticle film, charge generation after UV excitation appears after around 50 ps, but little is observed after visible pump excitation. In the nanoparticle film, as for a uniform film of the pure polymer, charge formation was efficiently induced by UV excitation pump, while excitation of the low energetic absorption states (at 610 nm) induces in the nanoparticle film a large optical gain region reducing the charge formation efficiency. It is proposed that the different intermolecular interactions and molecular order within the nanoparticles and mesoparticles are responsible for their markedly different photophysical behavior. These results therefore demonstrate the possibility of a hitherto unexplored route to stimulated emission in a conjugated polymer that has relatively undemanding film preparation requirements.https://www.mdpi.com/1420-3049/26/4/1138transient absorption spectroscopyconjugated polymersstimulated emissionnanoparticlesmesoparticles |
| spellingShingle | Mark Geoghegan Marta M. Mróz Chiara Botta Laurie Parrenin Cyril Brochon Eric Cloutet Eleni Pavlopoulou Georges Hadziioannou Tersilla Virgili Optical Gain in Semiconducting Polymer Nano and Mesoparticles Molecules transient absorption spectroscopy conjugated polymers stimulated emission nanoparticles mesoparticles |
| title | Optical Gain in Semiconducting Polymer Nano and Mesoparticles |
| title_full | Optical Gain in Semiconducting Polymer Nano and Mesoparticles |
| title_fullStr | Optical Gain in Semiconducting Polymer Nano and Mesoparticles |
| title_full_unstemmed | Optical Gain in Semiconducting Polymer Nano and Mesoparticles |
| title_short | Optical Gain in Semiconducting Polymer Nano and Mesoparticles |
| title_sort | optical gain in semiconducting polymer nano and mesoparticles |
| topic | transient absorption spectroscopy conjugated polymers stimulated emission nanoparticles mesoparticles |
| url | https://www.mdpi.com/1420-3049/26/4/1138 |
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