Investigations of bilayer sensor structure with copper phthalocyanine and palladium for hydrogen detection in SAW system

Bilayer structure with copper phthalocyanine (CuPc∼100nm) and palladium (∼18nm), has been studied for hydrogen gas-sensing application at ∼30°C and ∼50°C temperatures. The structure was fabricated in a two different vacuum deposition processes (first the CuPc film and than the Pd) onto a LiNbO 3 Y-cut Z-propagating substrate for a SAW method and additionally (in this same technological processes) onto a glass substrate with a planar microelectrode array for simultaneously monitoring of the structure planar resistance. A good correlation has been observed between this two methods - frequency changes for SAW method coincide with decreasing of the bilayer structure resistance. Although the simultaneously measurements not always were possible (too big resistance of the sample) they can give informations about the acoustoelectric interactions between SAW and charge carriers in the bi-layer structure.