Hydrogen gas sensitivity of thin films of tin oxide surface doped by platinum laser plasma of different structure and charge composition

The effect of structure and charge composition of Pt laser plasma in the surface doping of SnO2 thin films on their resistive gas sensitivity towards hydrogen has been studied. The structure and charge composition of plasma varied depending on the value and polarity of the potential (UD) of the inhomogeneous electrostatic field generated between a target and plates of a diaphragm located in a vacuum chamber outside the plasma dispersion zone under the action of Kr-F laser radiation on a platinum target. Doping at UD > 0 results in an increase in gas sensitivity of SnO2 films several times greater than doping by quasineutral plasma (UD = 0). The films doped at UD < 0 with surface concentrations of Pt optimum in terms of the maximum gas sensitivity appear to tolerant towards changes in the composition of the gas phase in a temperature range of 50-600°C. © 2009 Allerton Press, Inc.