Photo-Cross-Linkable Organic–Inorganic Hybrid Gate Dielectric for High Performance Organic Thin Film Transistors

Abstract

In this study, we have demonstrated a novel organic–inorganic hybrid gate dielectric material, zirconium tetraacrylate (ZrTA). ZrTA gate dielectric, where inorganic Zr elements are embedded in organic acrylate matrix, takes advantage of the complementary properties of single organic or inorganic gate dielectrics. A simple spin-coating and UV-assisted cross-linking reaction of acrylate moieties allowed ZrTA film to be photopatterned. The cross-linked ZrTA film by UV and heat treatments (UV, 365 nm for 3 min; heat, 120 °C for 30 min) showed high dielectric strength (10–7 A/cm2 at 2 MV/cm), and dielectric constant (5.48). In addition, surface properties of the ZrTA film (surface energy, surface roughness) were favorable for the growth of overlying pentacene organic semiconductor. Consequently, the organic thin-film transistor composed of a pentacene semiconductor and a cross-linked ZrTA gate dielectric displayed a moderately high field-effect mobility of 0.50 cm2/(V·s) with a negligible hysteresis transfer characteristic.