Perpustakaan Digital ITB

The ability to fabricate uniform and high-quality patterns of organicsemiconductors using a simple method is necessary to realize high-performance andreliable organicfield-effect transistors (OFETs) for practical applications. Here, wereport the facile fabrication of chemically patterned substrates in order to providesolvent wetting/dewetting regions and grow patterned crystals during blade coating ofa small-molecule semiconductor/insulating polymer blend solution. Polyurethaneacrylate is selected as the solvent dewetting material, not only because of itshydrophobicity but also because its patterns are easily produced by selective UVirradiation onto precursorfilms. 6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS-PEN) crystal patterns are grown on the line-shaped wetting regions of the patternedfilm, and the crystallinity of TIPS-PEN and alignment of molecules are found usingvarious crystal analysis tools depending on the pattern widths. The smallest width of 5?m yielded an OFET showing the highestfield-effect mobility value of 1.63 cm2/(V·s), which is much higher than the value of the OFET based on the unpatterned TIPS-PEN crystal. Notably, we demonstrateflexible and low-voltage-operating OFETs for practical use of the patterned crystals, andthe OFETs show highly stable operation under sustained gate bias stress thanks to the patterned crystals.