No Cover Image

E-Thesis 196 views 97 downloads

On the Relation Between Exciton Dynamics and Nano-Morphology in Organic Semiconductor Blends / Drew Riley

Swansea University Author: Drew Riley

  • Riley_Drew_PhD_Thesis_Final_Redacted_Signature.pdf

    PDF | E-Thesis – open access

    Copyright: The author, Drew B. Riley, 2023. Released under the terms of a Creative Commons Attribution-Only (CC-BY) License. Third party content is excluded for use under the license terms.

    Download (19.79MB)

DOI (Published version): 10.23889/SUthesis.62403

Abstract

Optoelectronic processes in semiconductor-based devices are widely understood through the constructs of highly-symmetric crystalline inorganic systems, where the lattice periodicity allows significant simplification. Emerging technologies, such as organic semiconductor-based devices, share many qual...

Full description

Published: Swansea 2023
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
Supervisor: Armin, Ardalan ; Sandberg, Oskar J. ; Meredith, Paul
URI: https://cronfa.swan.ac.uk/Record/cronfa62403
Tags: Add Tag
No Tags, Be the first to tag this record!
first_indexed 2023-01-23T13:07:14Z
last_indexed 2023-01-24T04:19:25Z
id cronfa62403
recordtype RisThesis
fullrecord <?xml version="1.0"?><rfc1807><datestamp>2023-01-23T14:02:17.8801890</datestamp><bib-version>v2</bib-version><id>62403</id><entry>2023-01-23</entry><title>On the Relation Between Exciton Dynamics and Nano-Morphology in Organic Semiconductor Blends</title><swanseaauthors><author><sid>edca1c48f922393fa2b3cb84d8dc0e4a</sid><firstname>Drew</firstname><surname>Riley</surname><name>Drew Riley</name><active>true</active><ethesisStudent>false</ethesisStudent></author></swanseaauthors><date>2023-01-23</date><deptcode>SPH</deptcode><abstract>Optoelectronic processes in semiconductor-based devices are widely understood through the constructs of highly-symmetric crystalline inorganic systems, where the lattice periodicity allows significant simplification. Emerging technologies, such as organic semiconductor-based devices, share many qualities with crys-talline inorganic semiconductors; however, they diverge in subtle yet important ways. Optical absorption in organic semiconductors gives rise to long-lived and tightly-bound excitons, which migrate in manner often disregarded in the un-derstanding of highly-symmetric crystalline inorganic semiconductors. Further, &#x2018;free&#x2019; charge carriers in organic semiconductors &#x2018;hop&#x2019; between organic molecules in a disordered film rather than the undergo band transport that delocalised car-riers in periodic lattices do. This hopping transport leads to lower charge carrier mobilities which have far-reaching ramifications to device operation.In the work summarised in this thesis the effect that excitonic and charge transport have on device performance of solar cells based on organic photo-voltaics will be explored. Experimental techniques are designed and developed to gain insight into the efficiency of exciton transport, the nanostructure of organic-semiconductor blends, and the relation between charge injection and extraction. Utilising these techniques, various state-of-the art systems are examined in detail and various pathways for improving device performance are voiced.Specifically, a technique to measure the exciton diffusion length in organic semiconductors is developed and shown to have many advantages over established techniques while improving the accuracy of the measurement. This technique is expanded to blends of organic semiconductors to quantify the efficiency of dif-fusion and quenching occurring between semiconductors in blends. This, along with a developed theoretical understanding, allows for the size of the phase sepa-rated domains to be quantified. Relationships between the excitons generated in organic semiconductors, charge carriers created in the blends, and the transport of charges to and extraction at the electrodes is considered in detail. Finally, a technique to distinguish between the nonradiative recombination occurring within an organic semiconductor blend and at the interface between the blend and the larger device structure is introduced. This technique utilises the well-establish reciprocity theory to reconcile the imbalance between charge injection and ex-traction unique to low-mobility organic semiconductors.</abstract><type>E-Thesis</type><journal/><volume/><journalNumber/><paginationStart/><paginationEnd/><publisher/><placeOfPublication>Swansea</placeOfPublication><isbnPrint/><isbnElectronic/><issnPrint/><issnElectronic/><keywords>Organic semiconductors, solar cells, physics, photoluminescence</keywords><publishedDay>13</publishedDay><publishedMonth>1</publishedMonth><publishedYear>2023</publishedYear><publishedDate>2023-01-13</publishedDate><doi>10.23889/SUthesis.62403</doi><url/><notes>ORCiD identifier: https://orcid.org/0000-0001-6688-0694</notes><college>COLLEGE NANME</college><department>Physics</department><CollegeCode>COLLEGE CODE</CollegeCode><DepartmentCode>SPH</DepartmentCode><institution>Swansea University</institution><supervisor>Armin, Ardalan ; Sandberg, Oskar J. ; Meredith, Paul</supervisor><degreelevel>Doctoral</degreelevel><degreename>Ph.D</degreename><degreesponsorsfunders>National Sciences and Engineering Council of Canada</degreesponsorsfunders><apcterm/><funders/><projectreference/><lastEdited>2023-01-23T14:02:17.8801890</lastEdited><Created>2023-01-23T13:04:02.1869568</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Biosciences, Geography and Physics - Physics</level></path><authors><author><firstname>Drew</firstname><surname>Riley</surname><order>1</order></author></authors><documents><document><filename>62403__26365__c4a80ca9a9c34099b1004ae0a0227693.pdf</filename><originalFilename>Riley_Drew_PhD_Thesis_Final_Redacted_Signature.pdf</originalFilename><uploaded>2023-01-23T13:26:52.1092986</uploaded><type>Output</type><contentLength>20747254</contentLength><contentType>application/pdf</contentType><version>E-Thesis &#x2013; open access</version><cronfaStatus>true</cronfaStatus><documentNotes>Copyright: The author, Drew B. Riley, 2023. Released under the terms of a Creative Commons Attribution-Only (CC-BY) License. Third party content is excluded for use under the license terms.</documentNotes><copyrightCorrect>true</copyrightCorrect><language>eng</language><licence>https://creativecommons.org/licenses/by/4.0/</licence></document></documents><OutputDurs/></rfc1807>
spelling 2023-01-23T14:02:17.8801890 v2 62403 2023-01-23 On the Relation Between Exciton Dynamics and Nano-Morphology in Organic Semiconductor Blends edca1c48f922393fa2b3cb84d8dc0e4a Drew Riley Drew Riley true false 2023-01-23 SPH Optoelectronic processes in semiconductor-based devices are widely understood through the constructs of highly-symmetric crystalline inorganic systems, where the lattice periodicity allows significant simplification. Emerging technologies, such as organic semiconductor-based devices, share many qualities with crys-talline inorganic semiconductors; however, they diverge in subtle yet important ways. Optical absorption in organic semiconductors gives rise to long-lived and tightly-bound excitons, which migrate in manner often disregarded in the un-derstanding of highly-symmetric crystalline inorganic semiconductors. Further, ‘free’ charge carriers in organic semiconductors ‘hop’ between organic molecules in a disordered film rather than the undergo band transport that delocalised car-riers in periodic lattices do. This hopping transport leads to lower charge carrier mobilities which have far-reaching ramifications to device operation.In the work summarised in this thesis the effect that excitonic and charge transport have on device performance of solar cells based on organic photo-voltaics will be explored. Experimental techniques are designed and developed to gain insight into the efficiency of exciton transport, the nanostructure of organic-semiconductor blends, and the relation between charge injection and extraction. Utilising these techniques, various state-of-the art systems are examined in detail and various pathways for improving device performance are voiced.Specifically, a technique to measure the exciton diffusion length in organic semiconductors is developed and shown to have many advantages over established techniques while improving the accuracy of the measurement. This technique is expanded to blends of organic semiconductors to quantify the efficiency of dif-fusion and quenching occurring between semiconductors in blends. This, along with a developed theoretical understanding, allows for the size of the phase sepa-rated domains to be quantified. Relationships between the excitons generated in organic semiconductors, charge carriers created in the blends, and the transport of charges to and extraction at the electrodes is considered in detail. Finally, a technique to distinguish between the nonradiative recombination occurring within an organic semiconductor blend and at the interface between the blend and the larger device structure is introduced. This technique utilises the well-establish reciprocity theory to reconcile the imbalance between charge injection and ex-traction unique to low-mobility organic semiconductors. E-Thesis Swansea Organic semiconductors, solar cells, physics, photoluminescence 13 1 2023 2023-01-13 10.23889/SUthesis.62403 ORCiD identifier: https://orcid.org/0000-0001-6688-0694 COLLEGE NANME Physics COLLEGE CODE SPH Swansea University Armin, Ardalan ; Sandberg, Oskar J. ; Meredith, Paul Doctoral Ph.D National Sciences and Engineering Council of Canada 2023-01-23T14:02:17.8801890 2023-01-23T13:04:02.1869568 Faculty of Science and Engineering School of Biosciences, Geography and Physics - Physics Drew Riley 1 62403__26365__c4a80ca9a9c34099b1004ae0a0227693.pdf Riley_Drew_PhD_Thesis_Final_Redacted_Signature.pdf 2023-01-23T13:26:52.1092986 Output 20747254 application/pdf E-Thesis – open access true Copyright: The author, Drew B. Riley, 2023. Released under the terms of a Creative Commons Attribution-Only (CC-BY) License. Third party content is excluded for use under the license terms. true eng https://creativecommons.org/licenses/by/4.0/
title On the Relation Between Exciton Dynamics and Nano-Morphology in Organic Semiconductor Blends
spellingShingle On the Relation Between Exciton Dynamics and Nano-Morphology in Organic Semiconductor Blends
Drew Riley
title_short On the Relation Between Exciton Dynamics and Nano-Morphology in Organic Semiconductor Blends
title_full On the Relation Between Exciton Dynamics and Nano-Morphology in Organic Semiconductor Blends
title_fullStr On the Relation Between Exciton Dynamics and Nano-Morphology in Organic Semiconductor Blends
title_full_unstemmed On the Relation Between Exciton Dynamics and Nano-Morphology in Organic Semiconductor Blends
title_sort On the Relation Between Exciton Dynamics and Nano-Morphology in Organic Semiconductor Blends
author_id_str_mv edca1c48f922393fa2b3cb84d8dc0e4a
author_id_fullname_str_mv edca1c48f922393fa2b3cb84d8dc0e4a_***_Drew Riley
author Drew Riley
author2 Drew Riley
format E-Thesis
publishDate 2023
institution Swansea University
doi_str_mv 10.23889/SUthesis.62403
college_str Faculty of Science and Engineering
hierarchytype
hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Biosciences, Geography and Physics - Physics{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Biosciences, Geography and Physics - Physics
document_store_str 1
active_str 0
description Optoelectronic processes in semiconductor-based devices are widely understood through the constructs of highly-symmetric crystalline inorganic systems, where the lattice periodicity allows significant simplification. Emerging technologies, such as organic semiconductor-based devices, share many qualities with crys-talline inorganic semiconductors; however, they diverge in subtle yet important ways. Optical absorption in organic semiconductors gives rise to long-lived and tightly-bound excitons, which migrate in manner often disregarded in the un-derstanding of highly-symmetric crystalline inorganic semiconductors. Further, ‘free’ charge carriers in organic semiconductors ‘hop’ between organic molecules in a disordered film rather than the undergo band transport that delocalised car-riers in periodic lattices do. This hopping transport leads to lower charge carrier mobilities which have far-reaching ramifications to device operation.In the work summarised in this thesis the effect that excitonic and charge transport have on device performance of solar cells based on organic photo-voltaics will be explored. Experimental techniques are designed and developed to gain insight into the efficiency of exciton transport, the nanostructure of organic-semiconductor blends, and the relation between charge injection and extraction. Utilising these techniques, various state-of-the art systems are examined in detail and various pathways for improving device performance are voiced.Specifically, a technique to measure the exciton diffusion length in organic semiconductors is developed and shown to have many advantages over established techniques while improving the accuracy of the measurement. This technique is expanded to blends of organic semiconductors to quantify the efficiency of dif-fusion and quenching occurring between semiconductors in blends. This, along with a developed theoretical understanding, allows for the size of the phase sepa-rated domains to be quantified. Relationships between the excitons generated in organic semiconductors, charge carriers created in the blends, and the transport of charges to and extraction at the electrodes is considered in detail. Finally, a technique to distinguish between the nonradiative recombination occurring within an organic semiconductor blend and at the interface between the blend and the larger device structure is introduced. This technique utilises the well-establish reciprocity theory to reconcile the imbalance between charge injection and ex-traction unique to low-mobility organic semiconductors.
published_date 2023-01-13T04:21:59Z
_version_ 1763754450588008448
score 11.024244

Similar Items