Effect of fullerene acceptor on the performance of solar cells based on PffBT4T-2OD
Abstract
We have studied bulk-heterojunction (BHJ) solar cells composed of the polymer PffBT4T-2OD as electron donor and three different electron accepting fullerenes, namely PC71BM, PC61BM and indene-C60-bis-adduct (ICBA) in order to understand the impact of different fullerenes on the morphology and efficiency of the corresponding photovoltaic devices. Despite PffBT4T-2OD:ICBA devices being characterised by higher values of Voc, they display the lowest power conversion efficiency (PCE) due to their lower Jsc and FF values. We find that although all blend films have similar morphologies, X-ray scattering indicates a reduced degree of order within the fullerene domains in the ICBA-based film. Due to the high LUMO level of ICBA, the corresponding blends are characterised by a lower initial exciton dissociation and this associated with the reduced ordering within the ICBA domains results in increased geminate recombination of the photogenerated electrons in the fullerene-rich domains and a consequently reduced PCE of the corresponding devices.
Citation
Zhang , Y , Parnell , A J , Blaszczyk , O , Musser , A J , Samuel , I D W , Lidzey , D G & Bernardo , G 2018 , ' Effect of fullerene acceptor on the performance of solar cells based on PffBT4T-2OD ' , Physical Chemistry Chemical Physics , vol. 20 , no. 28 , pp. 19023-19029 . https://doi.org/10.1039/c8cp02195c
Publication
Physical Chemistry Chemical Physics
Status
Peer reviewed
ISSN
1463-9076Type
Journal article
Description
Y. Z., O. B., and I. D. W. S. acknowledge financial support from the European Research Council (EXCITON grant 321305). I. D. W. S. acknowledges a Royal Society Wolfson Research Merit Award. G. B. thanks the European Commission for a Marie Sklodowska Curie Individual Fellowship (FP7/H2020 – Grant agreement number: 658391). We thank the EPSRC for financial support via grants EP/I028641/1 “Polymer/fullerene photovoltaic devices: new materials and innovative processes for high-volume manufacture”, EP/J017361/1 “Supergen Supersolar Hub”, EP/M025020/1 “High resolution mapping of performance and degradation mechanisms in printable photovoltaic devices” and EP/M025330/1, “Hybrid Polaritonics”.Collections
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