Abstract
Understanding the interrelationships between molecular structure and organic thin film transistor performance is key to the realization of novel organic semiconductors achieving superior device characteristics. Herein we report the synthesis, characterization, and charge-transporting properties in organic field-effect transistors (OFETs) of dithieno silole-based oligomers and copolymers having silacycloalkyl substituents. Silacyclization of the alkyl substituents on the silole silicon atom reduces steric encumbrance, contracts solid state intermolecular π-π contacts, and enhances the charge-transport capacity of the oligomers. Oligomer 3,3′-dihexylsilylene-2,2′:5, 2′′:5′,2′′′:5′′, 2′′′′:5′′′,2′′′ ′′-sexithiophene (SM5) with two Si-n-hexyl substituents is not FET-active, while the mobilities of 3,3′-cyclopentanylsilylene-2,2′: 5,2′′:5′,2′′′:5′′, 2′′′′:5′′′,2′′′ ′′′-sexithiophene (SM4) and 3,3′-cyclobutysilylene-2, 2′:5,2′′:5′,2′′′:5′′, 2′′′′:5′′′,2′′′ ′′-sexithiophene (SM3) FETs are 2.6 × 10-4 and 3.4 × 10-4 cm2/(V s), respectively. Single crystal structural data and melting point derived intermolecular packing trends parallel these FET results. Copolymers P1-P4 based on the same dithienosilole cycloalkyl cores exhibit optimized hole mobilities of 2 × 10-5, 6 × 10-4, 3 × 10-4, and 2 × 10-3 cm2/V•s, respectively, lower than that of analogous silole-containing polymers with long Si-alkyl substituents, implying that the solubilizing and self-assembly functions of Si-alkyl substituents are important for optimizing the mobility. Interestingly, copolymer [poly{[N,N′-bis(2- octyl-dodecyl)-1,4,5,8-naphthalenedicarboximide-2,6-diyl]-alt-5,5′-(3, 3′-cyclopentanylsilylene-2,2′-bithiophene (P5) films are the most ordered and exhibit a good electron mobility of 4 × 10-3 cm2/V•s after thermal annealing. All of these OFETs exhibit good ambient-stability, which is attributed to their low-lying HOMOs (>0.2 eV lower than that of P3HT), a consequence of introducing silole cores into polythiophene backbones.
| Original language | English |
|---|---|
| Pages (from-to) | 2185-2200 |
| Number of pages | 16 |
| Journal | Chemistry of Materials |
| Volume | 23 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - Apr 26 2011 |
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Keywords
- conjugated polymers
- sexithiophenes
- spiro siloles
- transistors
ASJC Scopus subject areas
- Materials Chemistry
- Chemical Engineering(all)
- Chemistry(all)
Cite this
Very large silacylic substituent effects on response in silole-based polymer transistors. / Huang, Hui; Youn, Jangdae; Ponce Ortiz, Rocio; Zheng, Yan; Facchetti, Antonio; Marks, Tobin J.
In: Chemistry of Materials, Vol. 23, No. 8, 26.04.2011, p. 2185-2200.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Very large silacylic substituent effects on response in silole-based polymer transistors
AU - Huang, Hui
AU - Youn, Jangdae
AU - Ponce Ortiz, Rocio
AU - Zheng, Yan
AU - Facchetti, Antonio
AU - Marks, Tobin J
PY - 2011/4/26
Y1 - 2011/4/26
N2 - Understanding the interrelationships between molecular structure and organic thin film transistor performance is key to the realization of novel organic semiconductors achieving superior device characteristics. Herein we report the synthesis, characterization, and charge-transporting properties in organic field-effect transistors (OFETs) of dithieno silole-based oligomers and copolymers having silacycloalkyl substituents. Silacyclization of the alkyl substituents on the silole silicon atom reduces steric encumbrance, contracts solid state intermolecular π-π contacts, and enhances the charge-transport capacity of the oligomers. Oligomer 3,3′-dihexylsilylene-2,2′:5, 2′′:5′,2′′′:5′′, 2′′′′:5′′′,2′′′ ′′-sexithiophene (SM5) with two Si-n-hexyl substituents is not FET-active, while the mobilities of 3,3′-cyclopentanylsilylene-2,2′: 5,2′′:5′,2′′′:5′′, 2′′′′:5′′′,2′′′ ′′′-sexithiophene (SM4) and 3,3′-cyclobutysilylene-2, 2′:5,2′′:5′,2′′′:5′′, 2′′′′:5′′′,2′′′ ′′-sexithiophene (SM3) FETs are 2.6 × 10-4 and 3.4 × 10-4 cm2/(V s), respectively. Single crystal structural data and melting point derived intermolecular packing trends parallel these FET results. Copolymers P1-P4 based on the same dithienosilole cycloalkyl cores exhibit optimized hole mobilities of 2 × 10-5, 6 × 10-4, 3 × 10-4, and 2 × 10-3 cm2/V•s, respectively, lower than that of analogous silole-containing polymers with long Si-alkyl substituents, implying that the solubilizing and self-assembly functions of Si-alkyl substituents are important for optimizing the mobility. Interestingly, copolymer [poly{[N,N′-bis(2- octyl-dodecyl)-1,4,5,8-naphthalenedicarboximide-2,6-diyl]-alt-5,5′-(3, 3′-cyclopentanylsilylene-2,2′-bithiophene (P5) films are the most ordered and exhibit a good electron mobility of 4 × 10-3 cm2/V•s after thermal annealing. All of these OFETs exhibit good ambient-stability, which is attributed to their low-lying HOMOs (>0.2 eV lower than that of P3HT), a consequence of introducing silole cores into polythiophene backbones.
AB - Understanding the interrelationships between molecular structure and organic thin film transistor performance is key to the realization of novel organic semiconductors achieving superior device characteristics. Herein we report the synthesis, characterization, and charge-transporting properties in organic field-effect transistors (OFETs) of dithieno silole-based oligomers and copolymers having silacycloalkyl substituents. Silacyclization of the alkyl substituents on the silole silicon atom reduces steric encumbrance, contracts solid state intermolecular π-π contacts, and enhances the charge-transport capacity of the oligomers. Oligomer 3,3′-dihexylsilylene-2,2′:5, 2′′:5′,2′′′:5′′, 2′′′′:5′′′,2′′′ ′′-sexithiophene (SM5) with two Si-n-hexyl substituents is not FET-active, while the mobilities of 3,3′-cyclopentanylsilylene-2,2′: 5,2′′:5′,2′′′:5′′, 2′′′′:5′′′,2′′′ ′′′-sexithiophene (SM4) and 3,3′-cyclobutysilylene-2, 2′:5,2′′:5′,2′′′:5′′, 2′′′′:5′′′,2′′′ ′′-sexithiophene (SM3) FETs are 2.6 × 10-4 and 3.4 × 10-4 cm2/(V s), respectively. Single crystal structural data and melting point derived intermolecular packing trends parallel these FET results. Copolymers P1-P4 based on the same dithienosilole cycloalkyl cores exhibit optimized hole mobilities of 2 × 10-5, 6 × 10-4, 3 × 10-4, and 2 × 10-3 cm2/V•s, respectively, lower than that of analogous silole-containing polymers with long Si-alkyl substituents, implying that the solubilizing and self-assembly functions of Si-alkyl substituents are important for optimizing the mobility. Interestingly, copolymer [poly{[N,N′-bis(2- octyl-dodecyl)-1,4,5,8-naphthalenedicarboximide-2,6-diyl]-alt-5,5′-(3, 3′-cyclopentanylsilylene-2,2′-bithiophene (P5) films are the most ordered and exhibit a good electron mobility of 4 × 10-3 cm2/V•s after thermal annealing. All of these OFETs exhibit good ambient-stability, which is attributed to their low-lying HOMOs (>0.2 eV lower than that of P3HT), a consequence of introducing silole cores into polythiophene backbones.
KW - conjugated polymers
KW - sexithiophenes
KW - spiro siloles
KW - transistors
UR - http://www.scopus.com/inward/record.url?scp=79955063419&partnerID=8YFLogxK
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U2 - 10.1021/cm200009k
DO - 10.1021/cm200009k
M3 - Article
VL - 23
SP - 2185
EP - 2200
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 8
ER -