Characteristics of pentacene organic thin-film transistors with PVP-TiO2 as a gate insulator

Abstract

The performance of OTFT with PVP-TiO2 composite, as a gate insulator, is reported, including the effect of surfactant for synthesizing the composite material. According to our investigation results, it was one of critical issues to prevent the aggregation of TiO2 particles during the synthesis process. From this point of view, TiO2 particles were treated u sing Tween80, as a surfactant, and we could reduce the aggregated TiO2 clusters. As a result, the OTFT with the composite insulator showed the threshold voltage of about -8.3 V and the subthreshold slope of about 1.5 V/decade, which are the optimized properties compared to those of OTFTs with bare PVP, in this study. It is thought that these characteristic improvements are originated from the increase in the dielectric constant of the PVP-based insulator by compositing with high-k-particles.