Abstract
The dependence of photoinduced carrier generation and decay on donor-acceptor nanomorphology is reported as a function of composition for blends of the polymer poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b] thiophene) (pBTTT-C14) with two electron-accepting fullerenes: phenyl-C71-butyric acid methyl ester (PC71BM) or the bisadduct of phenyl-C61-butyric acid methyl ester (bis-PC 61BM). The formation of partially or fully intercalated bimolecular crystals at weight ratios up to 1:1 for pBTTT-C14:PC71BM blends leads to efficient exciton quenching due to a combination of static and dynamic mechanisms. At higher fullerene loadings, pure PC71BM domains are formed that result in an enhanced free carrier lifetime, as a consequence of spatial separation of the electron and hole into different phases, and the dominant contribution to the photoconductance comes from the high-frequency electron mobility in the fullerene clusters. In the pBTTT-C14:bis- PC61BM system, phase separation results in a non-intercalated structure, independent of composition, which is characterized by exciton quenching that is dominated by a dynamic process, an enhanced carrier lifetime and a hole-dominated photoconductance signal. The results indicate that intercalation of fullerene into crystalline polymer domains is not detrimental to the density of long-lived carriers, suggesting that efficient organic photovoltaic devices could be fabricated that incorporate intercalated structures, provided that an additional pure fullerene phase is present for charge extraction.
| Original language | English |
|---|---|
| Pages (from-to) | 5635-5646 |
| Number of pages | 12 |
| Journal | ACS Nano |
| Volume | 5 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - Jul 26 2011 |
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Keywords
- blend
- conjugated polymer
- electron transfer
- fullerene
- intercalation
- photoconductance
ASJC Scopus subject areas
- Engineering(all)
- Materials Science(all)
- Physics and Astronomy(all)
Cite this
Photoinduced carrier generation and decay dynamics in intercalated and non-intercalated polymer : fullerene bulk heterojunctions. / Rance, William L.; Ferguson, Andrew J.; McCarthy-Ward, Thomas; Heeney, Martin; Ginley, David S.; Olson, Dana C.; Rumbles, Gary; Kopidakis, Nikos.
In: ACS Nano, Vol. 5, No. 7, 26.07.2011, p. 5635-5646.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Photoinduced carrier generation and decay dynamics in intercalated and non-intercalated polymer
T2 - fullerene bulk heterojunctions
AU - Rance, William L.
AU - Ferguson, Andrew J.
AU - McCarthy-Ward, Thomas
AU - Heeney, Martin
AU - Ginley, David S.
AU - Olson, Dana C.
AU - Rumbles, Gary
AU - Kopidakis, Nikos
PY - 2011/7/26
Y1 - 2011/7/26
N2 - The dependence of photoinduced carrier generation and decay on donor-acceptor nanomorphology is reported as a function of composition for blends of the polymer poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b] thiophene) (pBTTT-C14) with two electron-accepting fullerenes: phenyl-C71-butyric acid methyl ester (PC71BM) or the bisadduct of phenyl-C61-butyric acid methyl ester (bis-PC 61BM). The formation of partially or fully intercalated bimolecular crystals at weight ratios up to 1:1 for pBTTT-C14:PC71BM blends leads to efficient exciton quenching due to a combination of static and dynamic mechanisms. At higher fullerene loadings, pure PC71BM domains are formed that result in an enhanced free carrier lifetime, as a consequence of spatial separation of the electron and hole into different phases, and the dominant contribution to the photoconductance comes from the high-frequency electron mobility in the fullerene clusters. In the pBTTT-C14:bis- PC61BM system, phase separation results in a non-intercalated structure, independent of composition, which is characterized by exciton quenching that is dominated by a dynamic process, an enhanced carrier lifetime and a hole-dominated photoconductance signal. The results indicate that intercalation of fullerene into crystalline polymer domains is not detrimental to the density of long-lived carriers, suggesting that efficient organic photovoltaic devices could be fabricated that incorporate intercalated structures, provided that an additional pure fullerene phase is present for charge extraction.
AB - The dependence of photoinduced carrier generation and decay on donor-acceptor nanomorphology is reported as a function of composition for blends of the polymer poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b] thiophene) (pBTTT-C14) with two electron-accepting fullerenes: phenyl-C71-butyric acid methyl ester (PC71BM) or the bisadduct of phenyl-C61-butyric acid methyl ester (bis-PC 61BM). The formation of partially or fully intercalated bimolecular crystals at weight ratios up to 1:1 for pBTTT-C14:PC71BM blends leads to efficient exciton quenching due to a combination of static and dynamic mechanisms. At higher fullerene loadings, pure PC71BM domains are formed that result in an enhanced free carrier lifetime, as a consequence of spatial separation of the electron and hole into different phases, and the dominant contribution to the photoconductance comes from the high-frequency electron mobility in the fullerene clusters. In the pBTTT-C14:bis- PC61BM system, phase separation results in a non-intercalated structure, independent of composition, which is characterized by exciton quenching that is dominated by a dynamic process, an enhanced carrier lifetime and a hole-dominated photoconductance signal. The results indicate that intercalation of fullerene into crystalline polymer domains is not detrimental to the density of long-lived carriers, suggesting that efficient organic photovoltaic devices could be fabricated that incorporate intercalated structures, provided that an additional pure fullerene phase is present for charge extraction.
KW - blend
KW - conjugated polymer
KW - electron transfer
KW - fullerene
KW - intercalation
KW - photoconductance
UR - http://www.scopus.com/inward/record.url?scp=79961041295&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79961041295&partnerID=8YFLogxK
U2 - 10.1021/nn201251v
DO - 10.1021/nn201251v
M3 - Article
VL - 5
SP - 5635
EP - 5646
JO - ACS Nano
JF - ACS Nano
SN - 1936-0851
IS - 7
ER -