CO gas detection utilizing Pd-SnOx MIS heterostructure

The triangular voltage sweep method was used to study the device characteristics of Pd-SnO_x MIS heterostructure for detection of CO gas. An increase in area under the current peak in the J _p-V plot and a shift of current peak toward more positive gate bias voltages were found with increasing CO gas concentration in an O₂ or Ar environment. Results indicate that CO gas reacts with preadsorbed oxygen ions, which interact with positive ions in the SnO₂ oxide layer, thus increasing the number of positive ions in the oxide of the MIS capacitor. It is concluded that preadsorbed oxygen ions in the SnO₂ play a more important role than the lattice oxygen for CO gas detection in the Pd-SnO_x MIS heterostructure