Comparative gas sensing in copper porphyrin and copper phthalocyanine spin-coating films

Spin-coating films of tetra-(tert-butyl)-5,10,15,20-tetraazaporphyrin copper (CuTAP(t-Bu)4) and tetra-(tert-butyl) phthalocyanine copper (CuPc(t-Bu)4) was obtained and characterized by absorption spectra and atomic force microscopy. The gas sensing behaviors of the films were investigated with respect to NH3 and NO2 at room temperature. In addition, the interactions between complexes and gas analytes were also discussed. It was found that the devices exhibited better response and slow response–recovery times with increase of interactions between the complexes and analytes related with conjugated ability of complexes. This suggests that the response may imparted by use of strong interactions between the complexes and the analyte of interest at the expense of reversibility.