Enhancement of field-effect mobility and stability of poly(3-hexylthiophene) field-effect transistors by conformational change
SCIE
SCOPUS
- Title
- Enhancement of field-effect mobility and stability of poly(3-hexylthiophene) field-effect transistors by conformational change
- Authors
- Park, YD; Kim, DH; Lim, JA; Cho, JH; Jang, Y; Lee, WR; Park, JH; Cho, K
- Date Issued
- 2008-02-07
- Publisher
- AMER CHEMICAL SOC
- Abstract
- With the aim of enhancing the field-effect mobility and air stability of self-aligned regioregular poly(3-hexylthiophene), P3HT, by promoting two-dimensional molecular ordering, we transformed the chemical structure of the P3HT chain from a benzoid to a quinoid structure by doping the P3HT solution with HAuCl4 prior to film formation. We found that, for the appropriate HAuCl4 concentration, the P3HT nanocrystals adopt a highly ordered molecular structure with a field-effect mobility of 0.03 cm(2) V-1 s(-1), which is an improvement by a factor of more than 100. This increase in field-effect mobility is due to a significant enhancement of molecular ordering and the perpendicular orientation of the nanocrystals with respect to the insulator substrate. This resulted from the change in the P3HT chain conformation from a benzoid to a quinoid structure due to oxidation by HAuCl4. The quinoid structure favors a linear or expanded-coil conformation, so the thiophene inter-ring bonds have increased double-bond character, which improves the molecular ordering. Furthermore, the electrical properties of a doped P3HT device had highly improved stability to air without encapsulation. These results suggest that the effect of unintentional doping by oxygen on HALICl(4)-doped P3HT film is insignificant because the p-type doping effect of HAuCl4 is the major contributor.
- Keywords
- THIN-FILM TRANSISTORS; CONJUGATED POLYMERS; CHARGE-TRANSPORT; REGIOREGULAR POLY(3-HEXYLTHIOPHENE); SEMICONDUCTING POLYMERS; CARRIER DENSITY; POLYTHIOPHENE; CONDUCTIVITY; ELECTRONICS; STATE
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/22961
- DOI
- 10.1021/JP077125B
- ISSN
- 1932-7447
- Article Type
- Article
- Citation
- JOURNAL OF PHYSICAL CHEMISTRY C, vol. 112, no. 5, page. 1705 - 1710, 2008-02-07
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