Polymer: Nonfullerene Bulk Heterojunction Solar Cells with Exceptionally Low Recombination Rates

Journal article
(Original article)


Publication Details

Author(s): Gasparini N, Salvador MF, Heumüller T, Richter M, Classen A, Shrestha S, Matt G, Holliday S, Strohm S, Egelhaaf HJ, Wadsworth A, Baran D, Mcculloch I, Brabec C
Journal: Advanced Energy Materials
Publisher: Wiley-VCH Verlag
Publication year: 2017
ISSN: 1614-6832
eISSN: 1614-6840
Language: English


Abstract


Organic semiconductors are in general known to have an inherently lower charge carrier mobility compared to their inorganic counterparts. Bimolecular recombination of holes and electrons is an important loss mechanism and can often be described by the Langevin recombination model. Here, the device physics of bulk heterojunction solar cells based on a nonfullerene acceptor (IDTBR) in combination with poly(3-hexylthiophene) (P3HT) are elucidated, showing an unprecedentedly low bimolecular recombination rate. The high fill factor observed (above 65%) is attributed to non-Langevin behavior with a Langevin prefactor (β/βL) of 1.9 × 10-4. The absence of parasitic recombination and high charge carrier lifetimes in P3HT:IDTBR solar cells inform an almost ideal bimolecular recombination behavior. This exceptional recombination behavior is explored to fabricate devices with layer thicknesses up to 450 nm without significant performance losses. The determination of the photoexcited carrier mobility by time-of-flight measurements reveals a long-lived and nonthermalized carrier transport as the origin for the exceptional transport physics. The crystalline microstructure arrangement of both components is suggested to be decisive for this slow recombination dynamics. Further, the thickness-independent power conversion efficiency is of utmost technological relevance for upscaling production and reiterates the importance of understanding material design in the context of low bimolecular recombination. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.



FAU Authors / FAU Editors

Brabec, Christoph Prof. Dr.
Institute Materials for Electronics and Energy Technology (i-MEET)
Classen, Andrej
Institute Materials for Electronics and Energy Technology (i-MEET)
Gasparini, Nicola
Institute Materials for Electronics and Energy Technology (i-MEET)
Heumüller, Thomas Dr.-Ing.
Institute Materials for Electronics and Energy Technology (i-MEET)
Matt, Gebhard Dr.
Institute Materials for Electronics and Energy Technology (i-MEET)
Richter, Moses
Institute Materials for Electronics and Energy Technology (i-MEET)
Salvador, Michael Filipe Dr.
Institute Materials for Electronics and Energy Technology (i-MEET)
Shrestha, Shreetu
Institute Materials for Electronics and Energy Technology (i-MEET)


Additional Organisation
Graduiertenkolleg 1896/2 In situ Mikroskopie mit Elektronen, Röntgenstrahlen und Rastersonden
Exzellenz-Cluster Engineering of Advanced Materials


External institutions
Bayerisches Zentrum für Angewandte Energieforschung e.V. (ZAE Bayern)
Imperial College London / The Imperial College of Science, Technology and Medicine


How to cite

APA:
Gasparini, N., Salvador, M.F., Heumüller, T., Richter, M., Classen, A., Shrestha, S.,... Brabec, C. (2017). Polymer: Nonfullerene Bulk Heterojunction Solar Cells with Exceptionally Low Recombination Rates. Advanced Energy Materials. https://dx.doi.org/10.1002/aenm.201701561

MLA:
Gasparini, Nicola, et al. "Polymer: Nonfullerene Bulk Heterojunction Solar Cells with Exceptionally Low Recombination Rates." Advanced Energy Materials (2017).

BibTeX: 

Last updated on 2019-11-03 at 11:19