Comparative Study of Organic, Inorganic and Hybrid Gate-Dielectrics for Organic Field-Effect Transistors using Semiconducting Liquid-Crystal Polymers.

In this work, a novel semiconducting liquid-crystal polymer (LCP) for organic field-effect transistor (OFET) devices is evaluated exhibiting long range isotropic charge carrier transport properties due to the nature of forming homogenous crystalline domains over large areas during deposition. The investigations carried out throughout this work demonstrate a spread reduction of the OFET parameters by using the LCP allowing the fabrication of transistor devices in a simple processing procedure having similar device performance compared to a representative state-of-the-art organic semiconductor but with a higher reproducibility. Furthermore, interface-related impacts on the charge carrier mobility by using different kinds of dielectric materials (organic, inorganic and hybrid) and surface treatments is studied in order to estimate the feasibility of using the LCP material in a real application scenario. In this context, an evaluation environment on a smaller scale setting is established for all investigations carried out in this work on plastic substrates allowing dedicated and initial research for large-area processing on improved OFET stacks with new materials, composites and the involved interfaces.