Toward Improved Lifetimes of Organic Solar Cells under Thermal Stress: Substrate-Dependent Morphological Stability of PCDTBT:PCBM Films and Devices
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Morphological stability is a key requirement for outdoor operation of organic solar cells. We demonstrate that morphological stability and lifetime of polymer/fullerene based solar cells under thermal stress depend strongly on the substrate interface on which the active layer is deposited. In particular, we find that the stability of benchmark PCDTBT/PCBM solar cells under modest thermal stress is substantially increased in inverted solar cells employing a ZnO substrate compared to conventional devices employing a PEDOT:PSS substrate. This improved stability is observed to correlate with PCBM nucleation at the 50 nm scale, which is shown to be strongly influenced by different substrate interfaces. Employing this approach, we demonstrate remarkable thermal stability for inverted PCDTBT:PC70BM devices on ZnO substrates, with negligible (<2%) loss of power conversion efficiency over 160 h under 85 °C thermal stress and minimal thermally induced “burn-in” effect. We thus conclude that inverted organic solar cells, in addition to showing improved environmental stability against ambient humidity exposure as widely reported previously, can also demonstrate enhanced morphological stability. As such we show that the choice of suitable substrate interfaces may be a key factor in achieving prolonged lifetimes for organic solar cells under thermal stress conditions.
Date Issued
2015-10-15
Date Acceptance
2015-08-19
Citation
Scientific Reports, 2015, 5
ISSN
2045-2322
Publisher
Nature Publishing Group
Journal / Book Title
Scientific Reports
Volume
5
Copyright Statement
This work is licensed under a Creative Commons Attribution 4.0 International License. The
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Creative Commons license, users will need to obtain permission from the license holder to reproduce
the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
images or other third party material in this article are included in the article’s Creative Commons
license, unless indicated otherwise in the credit line; if the material is not included under the
Creative Commons license, users will need to obtain permission from the license holder to reproduce
the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
License URL
Sponsor
Engineering & Physical Science Research Council (E
Solvay Sa
Engineering & Physical Science Research Council (EPSRC)
Grant Number
n/a
4511500672-0001-MST
EP/K039946/1
Subjects
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
POLYMER
CRYSTALLIZATION
EFFICIENCY
BLENDS
TANDEM
STABILIZATION
LIGHT
Publication Status
Published
Article Number
15149