ZnO nanowire transistor inverter using top-gate electrodes with different work functions

ZnO-nanowire field effect transistors (FETs) with a top gate Al2O3 dielectric and different metal electrodes were fabricated to form a low voltage electrical inverter. Two FETs with Pd and Ni/Ti gates whose respective work functions are so different as 5.3 and 4.3 eV were chosen to play as driver and load, since such different work functions lead to a threshold voltage (VT) difference of at least 1 V between the two FETs. Our FETs with Pd and Ni/Ti, respectively, showed 0.8 and −0.3 V for their VT values, while our inverter exhibited a desirable voltage transfer characteristics with voltage gain of over 15 during low voltage electrical gating.