High-performance solution processed oxide TFT with aluminum oxide gate dielectric fabricated by a sol–gel method

We have studied the fabrication of solution processed aluminum-oxide (AlOx) gate dielectric at the maximum process temperature of 300 °C for a solution based zinc-tin-oxide (ZTO) thin-film-transistor (TFT). An AlOx layer was spin-coated from a solution of aluminum chloride (AlCl3) and then annealed at 300 °C for 1 h. The breakdown electrical field and leakage current density of the AlOx were found to be ∼4 MV cm−1 and 63 μA cm−2 at 1 MV cm−1, respectively. The ZTO layer was prepared by spin-coating or inkjet printing as an active layer of the TFT with AlOx gate dielectric and then annealed at 300 °C for 1 h. The TFT made using spin coating exhibited the field-effect mobility of 33 cm2 V−1s−1 in the saturation region, a gate swing of 96 mV dec.−1 and a threshold voltage of ∼1.2 V and the inkjet printed TFT showed a field-effect mobility of 24 cm2 V−1s−1.