Transport mechanism in sub 100°C processed high mobility Polycrystalline ZnO Transparent Thin Film Transistors

We demonstrate high performance ZnO TFTs with record field effect mobility 229 cm(2)/V.s, on/off ratio exceeding 10(7) (limited only by our simple device structure) and sub threshold swing (S) <150 mV/dec, surpassing the performance of many reported amorphous Indium Gallium Zinc Oxide (a-IGZO) thin film transistors.(1,2) The tail state distribution of the density of states (DOS) in ZnO extracted via 2D numerical simulations matched to experiment, demonstrates unequivocally a similar mobility mechanism that underpins all Transparent Conducting Oxides (TCOs)-whether amorphous or not. The characteristic Temperature of ZnO is found to be similar to 463 K and the tail state density of states (DOS) is similar to 1.3 x 10(20)cm(-3)eV(-1).