Synthesis and characterization of hysteresis-free zirconium oligosiloxane hybrid materials for organic thin film transistors

•A robust, solution processed zirconium oligosiloxane gate dielectric is demonstrated.•It shows long-term stability, high dielectric strength and low leakage current.•High electrical performance OTFTs and nearly hysteresis-free have been obtained.•The gate dielectric is suitable for fabricating reliable electronic devices.

Zirconium oligosiloxane resin was synthesized by a sol-gel reaction and UV-curing for organic thin film transistors (OTFTs) application. The synthesized resin has long-term stability and durability, which could be easily processed to produce a smooth coating on Si substrate. The dielectric constant of the film increased from 2.46 to 4.67 according to the variation of zirconium content. In addition, a low leakage current density of 10−6-10−7 A/cm2 at 2 MV/cm was obtained. Pentacene-based OTFTs were fabricated using the synthesized hybrimer as the gate dielectric layer, and their performances were optimized by tuning the ratio of zirconium and siloxane. Organic thin film transistors with zirconium oligosiloxane gate insulator were found to exhibit excellent performances with enhanced mobility at low applied voltage, a high on/off ratio, and nearly-hysteresis-free transfer characteristics.