Chemical changes in PCPDTBT:PCBM solar cells using XPS and TOF-SIMS and use of inverted device structure for improving lifetime performance

Hdl Handle:
http://hdl.handle.net/10034/558267
Title:
Chemical changes in PCPDTBT:PCBM solar cells using XPS and TOF-SIMS and use of inverted device structure for improving lifetime performance
Authors:
Kettle, Jeff; Waters, Huw; Ding, Ziqian; Horie, Masaki; Smith, Graham C.
Abstract:
Analysis of the degradation routes for poly[(4,4-bis(2-ethylhexyl)-cyclopenta-[2,1-b;3,4-b′]dithiophene)-2,6-diyl-alt-2,1,3-benzothiadiazole-4,7-diyl] (PCPDTBT)-based solar cells under illumination and in the presence of air have been conducted using a combination of X-ray Photoelectron Spectroscopy (XPS), Time-Of-Flight Secondary Ion Mass Spectrometry (TOF-SIMs) and solar cell device data. After ageing, XPS studies show that PCPDTBT appears as an oxygen-containing polymer, with data indicating that a break-up in the aromatic rings, formation of sulphates at the thiophene ring, chain scission in the polymer backbone and also loss of side chains. XPS studies have also been conducted on Phenyl-C71-butyric acid methyl ester (PC71BM) films and show a breakage of the fullerene cage, loss of molecular shape and oxidation of carbon atoms in the fullerene cage and side chains after ageing. XPS studies on active layers blends of PCPDTBT and PCBM also show significant changes in the vertical composition during ageing, with increased enrichment of PCPDTBT observed at the top surface and that the use of a processing additive (ODT) has a negative impact on the morphological stability. Based on these studies, it shown that inverted structures are better suited than non-inverted devices for PCPDTBT:PCBM solar cells. An additional advantage of inverted devices is shown using TOF-SIMS; electrode degradation during ageing experiments leads to migration of indium and tin ions into the active layer in non-inverted devices, but is eliminated for inverted devices.
Affiliation:
School of Electronic Engineering University of Bangor (Kettle, Waters, Ding), Department of Chemical Engineering National Tsing Hua University Taiwan (Horie), Department of Natural Sciences University of Chester (Smith)
Citation:
Kettle, J., Waters, H., Ding, Z., Horie, M., & Smith, G. C. (2015). Chemical changes in PCPDTBT:PCBM solar cells using XPS and TOF-SIMS and use of inverted device structure for improving lifetime performance. Solar Energy Materials and Solar Cells, 141, 139-147. doi: http://dx.doi.org/10.1016/j.solmat.2015.05.016
Publisher:
Elsevier
Journal:
Solar Energy Materials and Solar Cells
Publication Date:
10-Jun-2015
URI:
http://hdl.handle.net/10034/558267
DOI:
10.1016/j.solmat.2015.05.016
Additional Links:
http://linkinghub.elsevier.com/retrieve/pii/S0927024815002214
Type:
Article
Language:
en
ISSN:
0927-0248
Sponsors:
HW would like to thank Bangor University for financial support through his “125 scholarship” from the University. ZD is supported from the “SteelPV” project, which is funded from the EC’s Research Fund for Coal and Steel (RFCS) research programme under grant agreement number RFSR-CT-2014-00014. Finally, JK would like to thank the Royal Academy of Engineering for funding via the Newton Research Collaboration Programme (NRCP/1415/28).
Appears in Collections:
Natural Sciences

Full metadata record

DC FieldValue Language
dc.contributor.authorKettle, Jeffen
dc.contributor.authorWaters, Huwen
dc.contributor.authorDing, Ziqianen
dc.contributor.authorHorie, Masakien
dc.contributor.authorSmith, Graham C.en
dc.date.accessioned2015-06-19T13:54:41Zen
dc.date.available2015-06-19T13:54:41Zen
dc.date.issued2015-06-10en
dc.identifier.citationKettle, J., Waters, H., Ding, Z., Horie, M., & Smith, G. C. (2015). Chemical changes in PCPDTBT:PCBM solar cells using XPS and TOF-SIMS and use of inverted device structure for improving lifetime performance. Solar Energy Materials and Solar Cells, 141, 139-147. doi: http://dx.doi.org/10.1016/j.solmat.2015.05.016en
dc.identifier.issn0927-0248en
dc.identifier.doi10.1016/j.solmat.2015.05.016en
dc.identifier.urihttp://hdl.handle.net/10034/558267en
dc.description.abstractAnalysis of the degradation routes for poly[(4,4-bis(2-ethylhexyl)-cyclopenta-[2,1-b;3,4-b′]dithiophene)-2,6-diyl-alt-2,1,3-benzothiadiazole-4,7-diyl] (PCPDTBT)-based solar cells under illumination and in the presence of air have been conducted using a combination of X-ray Photoelectron Spectroscopy (XPS), Time-Of-Flight Secondary Ion Mass Spectrometry (TOF-SIMs) and solar cell device data. After ageing, XPS studies show that PCPDTBT appears as an oxygen-containing polymer, with data indicating that a break-up in the aromatic rings, formation of sulphates at the thiophene ring, chain scission in the polymer backbone and also loss of side chains. XPS studies have also been conducted on Phenyl-C71-butyric acid methyl ester (PC71BM) films and show a breakage of the fullerene cage, loss of molecular shape and oxidation of carbon atoms in the fullerene cage and side chains after ageing. XPS studies on active layers blends of PCPDTBT and PCBM also show significant changes in the vertical composition during ageing, with increased enrichment of PCPDTBT observed at the top surface and that the use of a processing additive (ODT) has a negative impact on the morphological stability. Based on these studies, it shown that inverted structures are better suited than non-inverted devices for PCPDTBT:PCBM solar cells. An additional advantage of inverted devices is shown using TOF-SIMS; electrode degradation during ageing experiments leads to migration of indium and tin ions into the active layer in non-inverted devices, but is eliminated for inverted devices.en
dc.description.sponsorshipHW would like to thank Bangor University for financial support through his “125 scholarship” from the University. ZD is supported from the “SteelPV” project, which is funded from the EC’s Research Fund for Coal and Steel (RFCS) research programme under grant agreement number RFSR-CT-2014-00014. Finally, JK would like to thank the Royal Academy of Engineering for funding via the Newton Research Collaboration Programme (NRCP/1415/28).en
dc.language.isoenen
dc.publisherElsevieren
dc.relation.urlhttp://linkinghub.elsevier.com/retrieve/pii/S0927024815002214en
dc.rightsArchived with thanks to Solar Energy Materials and Solar Cellsen
dc.subjectorganic photovoltaicsen
dc.subjectdegradationen
dc.subjectX-ray photoelectron spectroscopyen
dc.subjectinverted solar cellsen
dc.subjecttime of flight secondary ion mass spectrometryen
dc.titleChemical changes in PCPDTBT:PCBM solar cells using XPS and TOF-SIMS and use of inverted device structure for improving lifetime performanceen
dc.typeArticleen
dc.contributor.departmentSchool of Electronic Engineering University of Bangor (Kettle, Waters, Ding), Department of Chemical Engineering National Tsing Hua University Taiwan (Horie), Department of Natural Sciences University of Chester (Smith)en
dc.identifier.journalSolar Energy Materials and Solar Cellsen
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