초록 |
Polyimides (PI) have been widely known for their good mechanical and dielectric properties and excellent thermal and chemical tolerance in the field of electronic packages. Here, we proposed a water-based polyimide as gate dielectric for green chemistry to substitute harmful aprotic solvents that emit toxic vapors during drying process. We found that water-based precursor shows considerably better compatibility with facile thin film fabrication than N-methyl-2-pyrrolidone (NMP)-based precursor. To adopt the water-based precursor facilitates not only use of less thermal energy through faster imidization but escape from a hindrance in humid air through hydrolytic stability. As a result, pentacene-based TFTs, using water-based PI spin-coated in relative humidity (RH) of 43 %, exhibit average mobility of 0.062 cm2V-1s-1, on/off current ratio of 105, and high yield ratio nearly 100 %, which are in stark contrast to values of 0.020 cm2V-1s-1, 103, and 50 %, respectively, in NMP-based PI. |