Silver oxide Schottky contacts and metal semiconductor field-effect transistors on SnO2 thin films

Silver oxide Schottky contacts (SCs), reactively sputtered using a low-power Ar:O2 rf-plasma on SnO2 films grown by mist-CVD, showed significantly improved figures-of-merit compared with plain-metal SCs, with barrier heights of 0.91 eV and ideality factors close to unity. These SCs were used to fabricate thin-film metal-semiconductor FETs with on/off ratios >106 on the same solution-processed material. It is proposed that the high quality of these SCs is due to the oxidized fabrication methodology, whereby reactive oxygen species are likely to be present during the formation of the Schottky interface, leading to the removal of the native surface electron accumulation layer.