Effects of Alkyl Terminal Chains on Morphology, Charge Generation, Transport, and Recombination Mechanisms in Solution-Processed Small Molecule Bulk Heterojunction Solar Cells

Journal article
(Original article)


Publication Details

Author(s): Min J, Luponosov YN, Gasparini N, Richter M, Bakirov AV, Shcherbina MA, Chvalun SN, Grodd L, Grigorian S, Ameri T, Ponomarenko SA, Brabec C
Journal: Advanced Energy Materials
Publisher: Wiley-VCH Verlag
Publication year: 2015
Volume: 5
Journal issue: 17
ISSN: 1614-6832
eISSN: 1614-6840
Language: English


Abstract


Length of the terminal alkyl chains at dicyanovinyl (DCV) groups of two dithienosilole (DTS) containing small molecules (DTS(Oct)2-(2T-DCV-Me)2 and DTS(Oct)2-(2T-DCV-Hex)2) is investigated to evaluate how this affects the molecular solubility and blend morphology as well as their performance in bulk heterojunction organic solar cells (OSCs). While the DTS(Oct)2-(2T-DCV-Me)2 (a solubility of 5 mg mL-1) system exhibits both high short circuit current density (J sc) and high fill factor, the DTS(Oct)2-(2T-DCV-Hex)2 (a solubility of 24 mg mL-1) system in contrast suffers from a poor blend morphology as examined by atomic force morphology and grazing incidence X-ray scattering measurements, which limit the photovoltaic properties. The charge generation, transport, and recombination dynamics associated with the limited device performance are investigated for both systems. Nongeminate recombination losses in DTS(Oct)2-(2T-DCV-Hex)2 system are demonstrated to be significant by combining space charge limited current analysis and light intensity dependence of current-voltage characteristics in combination with photogenerated charge carrier extraction by linearly increasing voltage and transient photovoltage measurements. DTS(Oct)2-(2T-DCV-Me)2 in contrast performs nearly ideal with no evidence of nongeminate recombination, space charge effects, or mobility limitation. These results demonstrate the importance of alkyl chain engineering for solution-processed OSCs based on small molecules as an essential design tool to overcome transport limitations.



FAU Authors / FAU Editors

Ameri, Tayebeh Dr.
Institute Materials for Electronics and Energy Technology (i-MEET)
Brabec, Christoph Prof. Dr.
Institute Materials for Electronics and Energy Technology (i-MEET)
Gasparini, Nicola
Institute Materials for Electronics and Energy Technology (i-MEET)
Min, Jie
Institute Materials for Electronics and Energy Technology (i-MEET)
Richter, Moses
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
Interdisziplinäres Zentrum, Center for Nanoanalysis and Electron Microscopy (CENEM)


External institutions with authors

Russian Academy of Sciences / Росси́йская акаде́мия нау́к (RAS)
Universität Siegen


Research Fields

B Nanoelectronic Materials
Exzellenz-Cluster Engineering of Advanced Materials


How to cite

APA:
Min, J., Luponosov, Y.N., Gasparini, N., Richter, M., Bakirov, A.V., Shcherbina, M.A.,... Brabec, C. (2015). Effects of Alkyl Terminal Chains on Morphology, Charge Generation, Transport, and Recombination Mechanisms in Solution-Processed Small Molecule Bulk Heterojunction Solar Cells. Advanced Energy Materials, 5(17). https://dx.doi.org/10.1002/aenm.201500386

MLA:
Min, Jie, et al. "Effects of Alkyl Terminal Chains on Morphology, Charge Generation, Transport, and Recombination Mechanisms in Solution-Processed Small Molecule Bulk Heterojunction Solar Cells." Advanced Energy Materials 5.17 (2015).

BibTeX: 

Last updated on 2019-11-07 at 09:18