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Bar-coated high-performance organic thin-film transistors based on ultrathin PDFDT polymer with molecular weight independence.
- Source :
-
Organic Electronics . Feb2016, Vol. 29, p88-93. 6p. - Publication Year :
- 2016
-
Abstract
- We report high-performance organic thin-film transistors (OTFTs) with an ultrathin active layer of difluorobenzothiadiazole-dithienosilole copolymer (PDFDT) form by using the wire bar-coating process. The top-gate/bottom contact (TG/BC) OTFTs based on bar-coated PDFDT polymer as channel material and poly(methyl methacrylate) (PMMA) as gate dielectric show a hole mobility of up to 2.2 cm 2 V −1 s −1 with a current ON/OFF ratio ( I on / I off ) of 10 4 ∼10 5 , with the mobility being two times larger than that of the spin-coated PDFDT based OTFTs. The higher mobility of the bar-coated PDFDT polymer films can be attributed to the well-organized fibril structures of the polymer chains. Importantly, two different molecular weight polymers ( M n = 23 and 34 kDa) were employed to conduct these experiments and both batches showed about the same performance, which mitigates the typical batch-to-batch variation in OTFT performance. Furthermore, we explored the operational stability of the bar-coated OTFTs in ambient air and nitrogen environments. The bias-stress and cycling tests between the ON/OFF states of the bar-coated devices showed high stability in both nitrogen and air. Conclusively, here we demonstrate that (i) a simple bar-coating process is a better method to control and obtain good polymer morphology in comparison to spin-coating, and (ii) the PDFDT polymer has great potential to provide good reproducibility and stability in large-area OTFT devices. [ABSTRACT FROM AUTHOR]
- Subjects :
- *THIN films
*SURFACE coatings
*MOLECULAR weights
*POLYMERS
*FILM condensation
Subjects
Details
- Language :
- English
- ISSN :
- 15661199
- Volume :
- 29
- Database :
- Academic Search Index
- Journal :
- Organic Electronics
- Publication Type :
- Academic Journal
- Accession number :
- 112056488
- Full Text :
- https://doi.org/10.1016/j.orgel.2015.11.033