Low-temperature solution-processed high-k ZrTiOx dielectric films for high-performance organic thin film transistors

Abstract

Solution-processed high-k oxide dielectrics, significant for low-voltage organic thin film transistors (OTFTs), mostly rely on the high-temperature annealing process. Here, we report a simple 200°C hotplate-annealed zirconium titanium oxide (ZrTiOx) films with excellent dielectric properties for low-voltage OTFTs. The high dielectric constant of 27 and low leakage current of 1.5×10−6A/cm2 were achieved. Moreover, the pentacene-based OTFT with 200°C annealed ZrTiOx gate dielectrics realize high performances, such as the charge carrier mobility of 0.51cm2/Vs, on/off current ratio of 104, threshold voltage about −1.4V, and subtheshold voltage of 0.64V/dec at the low operating voltage of 6V. These performances are highly comparable to those with 500°C annealed ZrTiOx gate dielectrics. Moreover, our OTFTs show high hysteresis and aging stability, important for pratical applications. These results indicate that a simple low-temperature hotplate annealing can offer high-performance dielectrics for OTFTs, and provide a promising approach for low-power organic electronics at a low cost.