E. Laubender

Bimetallic nanoparticles for optimizing CMOS integrated SnO 2 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.

CMOS integrated tin dioxide gas sensors functionalized with bimetallic nanoparticles for improved carbon monoxide detection

In this work, we present the integration of functionalized tin dioxide gas sensors on CMOS fabricated microhotplate chips. Spray pyrolysis was used to deposit the gas sensitive films, with a thickness of 50 nm, on CMOS microhotplates. The SnO2 thin films were functionalized with noble bimetallic nanoparticles — PdAu — by inkjet printing and the influence of the nanoparticles on the sensor performance was evaluated. The functionalization of the CMOS integrated SnO2 sensors with PdAu nanoparticles lead to an almost three times higher sensor response towards carbon monoxide compared to the bare SnO2 thin film. The CMOS microhotplate chips are also applicable for 3D-integration of different gas sensing systems based on through-silicon-via technology. Building devices for daily life applications is possible with such 3D-integrated nanosensors.