PHOTOINDUCED DESORPTION IN FERROCENE-ETHANOL VAPOR SYSTEM USING POLYCHROMATIC-LIGHT SOURCE - DEPENDENCE ON LIGHT-INTENSITY

The photoeffects at 290 K on a ferrocene sample adsorbed with ethanol vapor in a sandwich-type of cell configuration have been studied with various intensities of light from a mercury lamp by monitoring electri cal current. Decrease in the measured current under light exposure has been observed at each light intensity. Termination of the light expos ure resulted in an enhancement in current value. The analysis of the r ates of the photoinduced changes in current under illumination at vari ous intensities indicated the photoinduced desorption of ethanol vapor from the ferrocene surface at each intensity of light used. Similar a nalysis of the rates of the change of current after the termination of light exposure indicated the possibility of re-adsorption of vapor by the sample. A mathematical analysis of the dependence of photoinduced cut-rent on the light intensities has been attempted. Similar studies have been extended for some ferrocene derivatives. The possibility of application of such photoinduced desorption in ethanol vapor sensors has been discussed. (C) 1998 Elsevier Science S.A.