Gas phase ion/molecule reactions in monogermane-hydrocarbon mixtures: a comparative Fourier transform Mass Spectrometry and Chemical Ionization Mass Spectrometry Study.

The gas phase ion/molecule reactions of GeH4 with some simple saturated (CH4, C2H6) and unsaturated hydrocarbons (C2H2, C3H4, C3H6) have been studied by high pressure mass spectrometry and Fourier transform mass spectrometry. The effects of the nature of the hydrocarbon and of the total pressure and the relative concentrations of the reagent gases on the formation of Ge?C containing ions are reported. Saturated hydrocarbons give only limited amounts of such species, whereas a variety of Ge?C containing products are efficiently produced when alkenes or alkynes are added to germane. In these latter cases, GeCH+3 and GeCH+5 are among the most abundant products, invariably accompanied by ions containing germanium, carbon and hydrogen in relative yields increasing with the hydrocarbon partial pressure. For all systems, the reaction pattern is presented and discussed in relation to the preparation of amorphous Ge?C containing materials for photovoltaic applications.