Sputtered SnO2:NiO thin films on self-assembled Au nanoparticle arrays for MEMS compatible NO2 gas sensors

Abstract

Abstract Here, heterostructured Au/SnO2:NiO thin films are fabricated by sputtering SnO2:NiO target onto the self-assembled Au nanoparticle (NPs, diameter ∼ 9.5\u2009nm) arrays and then activated by H2 annealing. Compared with the SnO2 and SnO2:NiO thin film counterparts, the 20\u2009nm thick Au/SnO2:NiO film shows the highest NO2 sensing performance after activated at optimized temperature of 500\u2009°C, with high response of ∼185 to 5\u2009ppm NO2, low detection limit of ∼50\u2009ppb, high selectivity, good stability and also low sensor-to-sensor variation of