Synthesis and characterization of combinatorial libraries of semiconductor gas sensors.

ABSTRACTWe have fabricated thin-film combinatorial gas sensor libraries based on doped semiconducting SnO2 thin films. The utility of combinatorial libraries is two-fold: one is to search and optimize the compositions for high sensitivity and selectivity of gases, and the other is to make use of the natural array geometry of the libraries with different sensor elements for electronic noses. Combinatorial pulsed-laser ablation was used to deposit compositionally varying arrays of sensor elements onto a pre-patterned device electrode configuration. Using a multiplexing electronics, we have demonstrated detection of chloroform, formaldehyde, and benzene gases at concentrations down to 12.5 ppm through pattern recognition of signals from the arrays of sensors.