1/ f noise analysis in high mobility polymer-based OTFTs with non-fluorinated dielectric

Abstract

In this paper, Low Frequency Noise (LFN) characterization of SP500 polymer-based Organic Thin Film Transistors with a nonfluorinated dielectric material is presented. The work aimed at identifying the mechanism of 1/f noise as well as inspecting the quality of the gate dielectric interface. Analysis of the LFN experimental data reveals that the 1/f noise power spectral density (PSD) follows 1/f γ frequency dependence over 1 Hz-10 kHz range. The normalized current noise PSD is found to vary similar to the squared-transconductance drain current ratio with respect to drain current, and is inversely related to the gate-area. Furthermore, the high carrier mobility (on the order of 2-3 cm 2 / Vs) obtained in these devices indicates that low density of traps exists in the semiconducting organic thin film. Such results ascribed the origin of 1/f noise to the dynamic exchange of charge carriers between the gate-dielectric traps and the channel. In addition, Nst values extracted from the 1/f noise experimental data reflect the enhanced quality of the gate dielectric and the interface it forms with the channel material.