Abstract
The phase-separation characteristics of spin-cast difluorinated- triethylsilylethynyl anthradithiophene (F-TESADT)/poly(methyl methacrylate) (PMMA) blends are investigated with the aim of fabricating transistors with a high field-effect mobility and stability. It is found that the presence of PMMA in the F-TESADT/PMMA blends prevents dewetting of F-TESADT from the substrate and provides a platform for F-TESADT molecules to segregate and crystallize at the air-film interface. By controlling the solvent evaporation rate of the spin-cast blend solution, it is possible to regulate the phase separation of the two components, which in turn determines the structural development of the F-TESADT crystals on PMMA. At a low solvent evaporation rate, a bilayer structure consisting of highly ordered F-TESAT crystals on the top and low-trap PMMA dielectric on the bottom can be fabricated by a one-step spin-casting process. The use of F-TESADT/PMMA blend films in bottom gate transistors produces much higher field-effect mobilities and greater stability than homo F-TESADT films because the phase-separated interface provides an efficient pathway for charge transport. By controlling the solvent evaporation rate of spin-cast difluorinated-triethylsilylethynyl anthradithiophene (F-TESADT)/poly(methyl methacrylate) (PMMA) blend solution, a bilayer structure consisting of highly ordered F-TESAT crystals on the top and low-trap PMMA dielectric on the bottom can be fabricated by a one-step process. The use of F-TESADT/PMMA blend films in transistors produces much higher field-effect mobilities and greater stability than homo F-TESADT films.
Original language | English |
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Pages (from-to) | 267-281 |
Number of pages | 15 |
Journal | Advanced Functional Materials |
Volume | 22 |
Issue number | 2 |
DOIs | |
State | Published - Jan 25 2012 |
Keywords
- organic field-effect transistors
- organic semiconductors
- phase separation
- soluble acene
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- General Chemistry
- Condensed Matter Physics
- General Materials Science
- Electrochemistry
- Biomaterials