Low-voltage and high-field-effect mobility organic transistors with a polymer insulator

A key issue in research into organic thin-film transistors (OTFTs) is low-voltage operation. In this study, we fabricated a pentacene thin-film transistor with an ultrathin layer of polyvinyl alcohol $\left(9\mathrm{nm}\right)$ as a gate insulator, and obtained a device with excellent electrical characteristics at low operating voltages (below $2\mathrm{V}$ ). This device was found to have a field-effect mobility of $1.1{\mathrm{cm}}^2∕\mathrm{V}\mathrm{s}$ , a threshold voltage of $-0.98\mathrm{V}$ , an exceptionally low subthreshold slope of $180\mathrm{mV}$ /decade, and an on/off current ratio of ${10}^6$ . This favorable combination of properties means that such OTFTs can be operated successfully at voltages below $2\mathrm{V}$ .