Photo Conductivity of Liquid Tetramethylsilane

Very few investigations have been carried out so far on the direct photo ionization of non-polar liquids. Vermeil et al. [1] detected an increase of conductivity in some liquid hydrocarbons when subjected to the light of rare gas resonance lamps. Recently similar experiments were performed by Casanovas and co-workers at the University of Toulouse [2, 3]. It was estimated that the ionization threshold energy of the molecules in the gas phase is reduced for the corresponding liquids by 0.5 eV to 1 eV. Direct measurements of the ionization threshold energy for liquid xenon were reported by Roberts and Wilson [4], Asaf and Steinberger [5] and Spear and LeComber [6]. While Roberts and Wilson found a strong increase of the photo current with photon energy above 8.9 eV, Asaf and Steinberger determined the threshold energy to 9.2 eV, which agrees with the value reported by Spear and LeComber. The photo ionization threshold in the liquid phase Ei, should be given by