Effective conversion processes of metal-oxide precursors for the reduction of the conversion temperature in solution processed metal-oxide thin-film transistors

Inhalt:
We report two different conversion pre-treatments of metal-oxide precursors used in metal-oxide thin-film transistors with the goal to reduce the conversion temperature of the precursors for the use on flexible substrates. On the one hand we used an oxygen plasma treatment prior to the thermal conversion to reduce the oxygen vacancies and the hydrocarbon content and on the other hand an UV laser annealing is used allowing annealing and structuring in one process step. For the O2 plasma treated transistors we achieved a field-effect mobility of muFE ≈ 4.8 cm²V(exp –1)s(exp –1), an on/off ratio of 10⁷ and a Vth = 2.5 V at a conversion temperature of 300 °C. Laser converted transistors prepared at a maximum processing temperature as low as 150 °C show a field-effect mobility of muFE = 0.9 cm²V(exp –1)s(exp –1) and a threshold voltage of Vth = –23 V.