Bimetallic nanoparticles for optimizing CMOS integrated SnO2 gas sensor devices

We present gas sensor devices based on ultrathin SnO₂ films, which are integrated on CMOS fabricated micro-hotplate (μhp) chips. Bimetallic nanoparticles (NPs) such as PdAu, PtAu, and PdPt have been synthesized for optimizing the sensing performance of these sensors. We demonstrate that functionalization of nanocrystalline SnO₂ gas sensing films with PdAu-NPs leads to a strongly improved sensitivity to the toxic gas carbon monoxide (CO) while the cross sensitivity to humidity is almost completely suppressed. We conclude that specific functionalization of CMOS integrated SnO₂ thin film gas sensors with different types of NPs is a powerful strategy towards sensor arrays capable for distinguishing several target gases. Such CMOS integrated arrays are highly promising candidates for realizing smart multi-parameter sensing devices for the consumer market.