Thickness-dependent sensitivity of Copper Phthalocyanine chemiresistive Nitrogen Dioxide sensors

Chemiresistors of varying Copper Phthalocyanine sensing layer thickness, from 10 to 350 nm, have been fabricated and tested for sensing to sub-ppm levels of Nitrogen Dioxide. The results obtained were analyzed and the kinetics was shown to correlate well with first order kinetics, rather than with Elovich model. In explaining the sensitivity trend to thickness variation, gas diffusion into the layer was found to play a role and should be taken into consideration.