AVS 49th International Symposium
    Homeland Security Wednesday Sessions
       Session HS+SS+BI-WeA

Paper HS+SS+BI-WeA10
Metal Phthalocyanine Thin Films as Gas Sensors

Wednesday, November 6, 2002, 5:00 pm, Room C-209

Session: Chemical and Biological Detection
Presenter: L. Lozzi, INFM and University of L'Aquila, Italy
Authors: L. Lozzi, INFM and University of L'Aquila, Italy
S. Santucci, INFM and University of L'Aquila, Italy
C. Cantalini, University of L'Aquila, Italy
Correspondent: Click to Email
Metal Phthalocyanine (MPc) thin films have shown interesting properties as gas sensor, in particular for NO2. The wide variety of different available molecules, changing both the central atom and/or the chemical structure of the outer benzene rings, allows a fine modulation of the film sensing properties. In this work we will present our result on the interaction between oxidating gases (O2 and NO2) and different MPc films. We have deposited thin films (about 50 nm thick) of Copper Phthalocyanine (CuPc) and Exadecafluoro-copper-phthalocyanine (F16CuPc) onto Si3N4 substrates, for the spectroscopic characterizations, and onto Pt interdigital circuits, for the gas sensing tests. These films have been analysed both as deposited and after different thermal annealing. The electrical sensing analyses have shown a sizeable decrease of the film resistivity during the film exposure to NO2, even at very low concentration (up to 100 ppb). We have studied the electronic structure by means of the X-ray and ultraviolet photoemission spectroscopies (XPS-UPS) after the exposure to NO2 and O2 both at room and at higher temperature, in order to investigate the surface reactivity of these samples and in particular the preferential adsorption sites.