NITROGEN-OXIDE GAS SENSOR-BASED ON TETRA-TERTBUTYL COPPER PHTHALOCYANINE LANGMUIR-BLODGETT-FILMS

A novel attempt to improve the parameters of a NOx sensor, based on co nductivity modulation, is presented. By using tetra-tertbutyl copper p hthalocyanine (ttb CuPc) Langmuir-Blodgett (LB) films characterized by high conductivity (10(-6) Sm cm(-1)) and thermostability (up to 160 d egrees C) the detection of low NOx levels (0.1-10(3) ppm) in air is de monstrated. The response time and the sensitivity are similar to 1 min and 6 nA per decade of NOx concentration respectively. The selectivit y of such a sensor could be explained by the difference of the conduct ivity activation energies for NOx (0.63 eV) and oxygen (0.79 eV).