Abstract
A strong modification of the electronic properties of solution-processable conjugated polythiophenes by self-assembled silane molecules is reported. Upon bulk doping with hydrolized fluoroalkyl trichlorosilane, the electrical conductivity of ultrathin polythiophene films increases by up to six orders of magnitude, reaching record values for polythiophenes: (1.1±0.1) ×103S cm-1 for poly(2,5-bis(3-tetradecylthiophen -2-yl)thieno[3,2-b]thiophene) (PBTTT) and 50±20 S cm-1 for poly(3-hexyl)thiophene (P3HT). Interband optical absorption of the polymers in the doped state is drastically reduced, making these highly conductive films transparent in the visible range. The dopants within the porous polymer matrix are partially crosslinked via a silane self-polymerization mechanism that makes the samples very stable in vacuum and nonpolar environments. The mechanism of SAM-induced conductivity is believed to be based on protonic doping by the free silanol groups available within the partially crosslinkedSAMnetwork incorporated in the polythiophene structure. The SAM-doped polythiophenes exhibit an intrinsic sensing effect: a drastic and reversible change in conductivity in response to ambient polar molecules, which is believed to be due to the interaction of the silanol groups with polar analytes. The reported electronic effects point to a new attractive route for doping conjugated polymers with potential applications in transparent conductors and molecular sensors.
| Original language | English |
|---|---|
| Pages (from-to) | 1906-1911 |
| Number of pages | 6 |
| Journal | Advanced Functional Materials |
| Volume | 19 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Jun 23 2009 |
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ASJC Scopus subject areas
- Biomaterials
- Electrochemistry
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials
Cite this
Doping of conjugated polythiophenes with alkyl silanes. / Kao, Chi Yueh; Lee, Bumsu; Wielunski, Leszek S.; Heeney, Martin; McCulloch, Iain; Garfunkel, Eric; Feldman, Leonard C; Podzorov, Vitaly.
In: Advanced Functional Materials, Vol. 19, No. 12, 23.06.2009, p. 1906-1911.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Doping of conjugated polythiophenes with alkyl silanes
AU - Kao, Chi Yueh
AU - Lee, Bumsu
AU - Wielunski, Leszek S.
AU - Heeney, Martin
AU - McCulloch, Iain
AU - Garfunkel, Eric
AU - Feldman, Leonard C
AU - Podzorov, Vitaly
PY - 2009/6/23
Y1 - 2009/6/23
N2 - A strong modification of the electronic properties of solution-processable conjugated polythiophenes by self-assembled silane molecules is reported. Upon bulk doping with hydrolized fluoroalkyl trichlorosilane, the electrical conductivity of ultrathin polythiophene films increases by up to six orders of magnitude, reaching record values for polythiophenes: (1.1±0.1) ×103S cm-1 for poly(2,5-bis(3-tetradecylthiophen -2-yl)thieno[3,2-b]thiophene) (PBTTT) and 50±20 S cm-1 for poly(3-hexyl)thiophene (P3HT). Interband optical absorption of the polymers in the doped state is drastically reduced, making these highly conductive films transparent in the visible range. The dopants within the porous polymer matrix are partially crosslinked via a silane self-polymerization mechanism that makes the samples very stable in vacuum and nonpolar environments. The mechanism of SAM-induced conductivity is believed to be based on protonic doping by the free silanol groups available within the partially crosslinkedSAMnetwork incorporated in the polythiophene structure. The SAM-doped polythiophenes exhibit an intrinsic sensing effect: a drastic and reversible change in conductivity in response to ambient polar molecules, which is believed to be due to the interaction of the silanol groups with polar analytes. The reported electronic effects point to a new attractive route for doping conjugated polymers with potential applications in transparent conductors and molecular sensors.
AB - A strong modification of the electronic properties of solution-processable conjugated polythiophenes by self-assembled silane molecules is reported. Upon bulk doping with hydrolized fluoroalkyl trichlorosilane, the electrical conductivity of ultrathin polythiophene films increases by up to six orders of magnitude, reaching record values for polythiophenes: (1.1±0.1) ×103S cm-1 for poly(2,5-bis(3-tetradecylthiophen -2-yl)thieno[3,2-b]thiophene) (PBTTT) and 50±20 S cm-1 for poly(3-hexyl)thiophene (P3HT). Interband optical absorption of the polymers in the doped state is drastically reduced, making these highly conductive films transparent in the visible range. The dopants within the porous polymer matrix are partially crosslinked via a silane self-polymerization mechanism that makes the samples very stable in vacuum and nonpolar environments. The mechanism of SAM-induced conductivity is believed to be based on protonic doping by the free silanol groups available within the partially crosslinkedSAMnetwork incorporated in the polythiophene structure. The SAM-doped polythiophenes exhibit an intrinsic sensing effect: a drastic and reversible change in conductivity in response to ambient polar molecules, which is believed to be due to the interaction of the silanol groups with polar analytes. The reported electronic effects point to a new attractive route for doping conjugated polymers with potential applications in transparent conductors and molecular sensors.
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U2 - 10.1002/adfm.200900120
DO - 10.1002/adfm.200900120
M3 - Article
AN - SCOPUS:67649206021
VL - 19
SP - 1906
EP - 1911
JO - Advanced Functional Materials
JF - Advanced Functional Materials
SN - 1616-301X
IS - 12
ER -