Large-area(64 × 64 array) inkjet-printed high-performance metal oxide bilayer heterojunction thin film transistors and n-metal-oxide-semiconductor(NMOS) inverters

It is a big challenge to construct large-scale,high-resolution and high-performance inkjet-printed metal oxide thin film transistor(TFT)arrays with independent gates for the new printed displays.Here,a self-confined inkjet printing technology has been developed to construct large-area(64×64 array),high-resolution and high-performance metal oxide bilayer(In_(2)O_(3)/IGZO)heterojunction TFTs with independent bottom gates on transparent glass substrates.Inkjet printing In_(2)O_(3) dot arrays with the diameters from 55 to 70μm and the thickness of~10 nm were firstly deposited on UV/ozone treated AlO_(x) dielectric layers,and then IGZO dots were selectively printed on the top of In_(2)O_(3) dots by self-confined technology to form In_(2)O_(3)/IGZO heterojunction channels.When the inkjet-printed IO layers treated by UV/ozone for more than 30 min or oxygen plasma for 5 min prior to print IGZO thin films,the mobility of the resulting printed In_(2)O_(3)/IGZO heterojunction TFTs are correspondingly enhanced to be 18.80 and 28.44 cm^(2) V^(-1) s^(-1) with excellent on/off ratios(>10^(8))and negligible hysteresis.Furthermore,the printed N-Metal-Oxide-Semiconductor(NMOS)inverter consisted of an In_(2)O_(3)/IGZO TFT and an IGZO TFT has been demonstrated,which show excellent performance with the voltage gain up to 112.The strategy demonstrated here can be considered as general approaches to realize a new generation of high-performance printed logic gates,circuits and display driving circuits.