Pentacene-based thin film transistors with titanium oxide-polystyrene/polystyrene insulator blends:: High mobility on high K dielectric films

High K titanium oxide-polystyrene TiO2-PS nanocomposite has been blended with PS to generate gate dielectric films with permittivities ranging from 2.5 to 8 in order to investigate permittivity effects on pentacene thin film transistor performance. An order of magnitude increase in saturation mobility is observed for TiO2-PS (K=8) as compared to PS devices (K=2.5). Morphological differences for pentacene grown on TiO2-PS/PS dielectrics are thought to be responsible for the observed mobility enhancements. The high performance of pentacene on TiO2-PS devices suggests that high permittivity films are compatible with high mobility devices. (c) 2007 American Institute of Physics.