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Investigating electron-transfer processes of supramolecular donor-acceptor complexes using femtosecond transient absorption spectroscopy
Dissertation (MSc)--University of Pretoria, 2019.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2019
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| _version_ | 1867613547724275712 |
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| access_status_str | Open Access |
| author2 | Kruger, T.P.J. (Tjaart) |
| author_browse | Kruger, T.P.J. (Tjaart) |
| author_facet | Kruger, T.P.J. (Tjaart) |
| collection | Thesis |
| dc_rights_str_mv | © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc)--University of Pretoria, 2019. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/70584 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:37:53.400Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2019 |
| publishDateRange | 2019 |
| publishDateSort | 2019 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/70584 Investigating electron-transfer processes of supramolecular donor-acceptor complexes using femtosecond transient absorption spectroscopy Kruger, T.P.J. (Tjaart) u10692143@tuks.co.za Radhakrishnan, Shankara Gayathri Harrison, Arthur Justin UCTD Dissertation (MSc)--University of Pretoria, 2019. A femtosecond transient absorption spectroscopy system was developed and used to characterize the charge-transfer processes which take place between photo-excited porphyrin and C60-fullerene supramolecular donor-acceptor complexes, specifically the free-base (TPP) and zinc metal porphyrins (ZnTPP). A comprehensive photophysical characterization of the TPP-C60 and ZnTPPC60 complexes, along with the individual moieties, was performed which included ground-state absorption, steady-state fluorescence, and femtosecond transient absorption spectroscopic data, from which Jablonski diagrams and kinetic models could be constructed. The electron transfer processes were monitored along spectral traces at 1000 nm in the difference absorption spectra, where the C 60 anion appears. Upon photo-excitation at 387.5 nm with pulses of 150 fs time-duration and pump beam fluency of 1.02 mJ/cm2, the kinetic rates of charge-separation (kCS) from donor to acceptor were determined to be 8.3 1011 s1 (1.2 ps) and 5.5 1011 s1 (1.8 ps) for the TPP-C60 and ZnTPP-C60 complexes, respectively. Charge-recombination (kCR) rates from the acceptor to donor were 8.4 109 s1 (119 ps) and 5.4 109 s1 (183 ps) for the TPP-C60 and ZnTPP-C60 complexes, respectively. The ratio of chargeseparation and charge-recombination kinetic rates (kCS/kCR) exceeded 100 for both TPP-C60 and ZnTPP-C60 complexes, showing that these simple, selfassembled, supramolecular complexes have the ability to extend the process of charge-recombination after fast separation, a key characteristic necessary for an effective solar cell. Physics MSc Unrestricted 2019-07-08T09:46:55Z 2019-07-08T09:46:55Z 2019/04/11 2019 Dissertation Harrison, AJ 2019, Investigating electron-transfer processes of supramolecular donor-acceptor complexes using femtosecond transient absorption spectroscopy, MSc Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/70584> A2019 http://hdl.handle.net/2263/70584 en © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Investigating electron-transfer processes of supramolecular donor-acceptor complexes using femtosecond transient absorption spectroscopy |
| title | Investigating electron-transfer processes of supramolecular donor-acceptor complexes using femtosecond transient absorption spectroscopy |
| title_full | Investigating electron-transfer processes of supramolecular donor-acceptor complexes using femtosecond transient absorption spectroscopy |
| title_fullStr | Investigating electron-transfer processes of supramolecular donor-acceptor complexes using femtosecond transient absorption spectroscopy |
| title_full_unstemmed | Investigating electron-transfer processes of supramolecular donor-acceptor complexes using femtosecond transient absorption spectroscopy |
| title_short | Investigating electron-transfer processes of supramolecular donor-acceptor complexes using femtosecond transient absorption spectroscopy |
| title_sort | investigating electron transfer processes of supramolecular donor acceptor complexes using femtosecond transient absorption spectroscopy |
| topic | UCTD |
| url | http://hdl.handle.net/2263/70584 |