Abstract
Non-fullerene acceptors based on perylenediimides (PDIs) have garnered significant interest as an alternative to fullerene acceptors in organic photovoltaics (OPVs), but their charge transport phenomena are not well understood, especially in bulk heterojunctions (BHJs). Here, charge transport and current fluctuations are investigated by performing correlated low-frequency noise and impedance spectroscopy measurements on two BHJ OPV systems, one employing a fullerene acceptor and the other employing a dimeric PDI acceptor. In the dark, these measurements reveal that PDI-based OPVs have a greater degree of recombination in comparison to fullerene-based OPVs. Furthermore, for the first time in organic solar cells, 1/f noise data are fit to the Kleinpenning model to reveal underlying current fluctuations in different transport regimes. Under illumination, 1/f noise increases by approximately four orders of magnitude for the fullerene-based OPVs and three orders of magnitude for the PDI-based OPVs. An inverse correlation is also observed between noise spectral density and power conversion efficiency. Overall, these results show that low-frequency noise spectroscopy is an effective in situ diagnostic tool to assess charge transport in emerging photovoltaic materials, thereby providing quantitative guidance for the design of next-generation solar cell materials and technologies.
| Original language | English |
|---|---|
| Article number | 1703805 |
| Journal | Advanced Functional Materials |
| Volume | 27 |
| Issue number | 48 |
| DOIs | |
| Publication status | Published - Dec 22 2017 |
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Keywords
- 1/f noise
- alternate acceptors
- organic photovoltaics
- PBDTTT-EFT
- PCBM
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Condensed Matter Physics
- Electrochemistry
Cite this
Correlated In Situ Low-Frequency Noise and Impedance Spectroscopy Reveal Recombination Dynamics in Organic Solar Cells Using Fullerene and Non-Fullerene Acceptors. / Luck, Kyle A.; Sangwan, Vinod K.; Hartnett, Patrick E.; Arnold, Heather N.; Wasielewski, Michael R; Marks, Tobin J; Hersam, Mark C.
In: Advanced Functional Materials, Vol. 27, No. 48, 1703805, 22.12.2017.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Correlated In Situ Low-Frequency Noise and Impedance Spectroscopy Reveal Recombination Dynamics in Organic Solar Cells Using Fullerene and Non-Fullerene Acceptors
AU - Luck, Kyle A.
AU - Sangwan, Vinod K.
AU - Hartnett, Patrick E.
AU - Arnold, Heather N.
AU - Wasielewski, Michael R
AU - Marks, Tobin J
AU - Hersam, Mark C
PY - 2017/12/22
Y1 - 2017/12/22
N2 - Non-fullerene acceptors based on perylenediimides (PDIs) have garnered significant interest as an alternative to fullerene acceptors in organic photovoltaics (OPVs), but their charge transport phenomena are not well understood, especially in bulk heterojunctions (BHJs). Here, charge transport and current fluctuations are investigated by performing correlated low-frequency noise and impedance spectroscopy measurements on two BHJ OPV systems, one employing a fullerene acceptor and the other employing a dimeric PDI acceptor. In the dark, these measurements reveal that PDI-based OPVs have a greater degree of recombination in comparison to fullerene-based OPVs. Furthermore, for the first time in organic solar cells, 1/f noise data are fit to the Kleinpenning model to reveal underlying current fluctuations in different transport regimes. Under illumination, 1/f noise increases by approximately four orders of magnitude for the fullerene-based OPVs and three orders of magnitude for the PDI-based OPVs. An inverse correlation is also observed between noise spectral density and power conversion efficiency. Overall, these results show that low-frequency noise spectroscopy is an effective in situ diagnostic tool to assess charge transport in emerging photovoltaic materials, thereby providing quantitative guidance for the design of next-generation solar cell materials and technologies.
AB - Non-fullerene acceptors based on perylenediimides (PDIs) have garnered significant interest as an alternative to fullerene acceptors in organic photovoltaics (OPVs), but their charge transport phenomena are not well understood, especially in bulk heterojunctions (BHJs). Here, charge transport and current fluctuations are investigated by performing correlated low-frequency noise and impedance spectroscopy measurements on two BHJ OPV systems, one employing a fullerene acceptor and the other employing a dimeric PDI acceptor. In the dark, these measurements reveal that PDI-based OPVs have a greater degree of recombination in comparison to fullerene-based OPVs. Furthermore, for the first time in organic solar cells, 1/f noise data are fit to the Kleinpenning model to reveal underlying current fluctuations in different transport regimes. Under illumination, 1/f noise increases by approximately four orders of magnitude for the fullerene-based OPVs and three orders of magnitude for the PDI-based OPVs. An inverse correlation is also observed between noise spectral density and power conversion efficiency. Overall, these results show that low-frequency noise spectroscopy is an effective in situ diagnostic tool to assess charge transport in emerging photovoltaic materials, thereby providing quantitative guidance for the design of next-generation solar cell materials and technologies.
KW - 1/f noise
KW - alternate acceptors
KW - organic photovoltaics
KW - PBDTTT-EFT
KW - PCBM
UR - http://www.scopus.com/inward/record.url?scp=85038426540&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85038426540&partnerID=8YFLogxK
U2 - 10.1002/adfm.201703805
DO - 10.1002/adfm.201703805
M3 - Article
VL - 27
JO - Advanced Functional Materials
JF - Advanced Functional Materials
SN - 1616-301X
IS - 48
M1 - 1703805
ER -