GAS-PHASE ION CHEMISTRY IN METHYLGERMANE AND METHYLGERMANE SILANE/

The rate constants of the gas phase ion/molecule reactions in CH3CeH3 alone and in CH3GeH3/SiH4 mixture have been determined by ion trap mas s spectrometry and compared with those obtained in GeH4 and CH3SiH3 al one, and in CeH4/SiH4 mixture. Collision rate constants have been calc ulated and efficiencies determined. Chain propagation of ions containi ng Ge, Si, and, possibly C, important in the radiolytical preparation of materials of interest in photovoltaic technology, occurs through io ns such as GeSiCHn+ (n = 4, 6) from Si2Hn+ (n = 2, 4) reacting with me thylgermane and GeSi2CHn+ (n = 6, 7) from Si3Hn+ (n = 4, 5) reacting w ith methylgermane at rather high rates. The experimental conditions to increase yield of formation of ions with silicon and germanium are di scussed. (C) 1998 Elsevier Science B.V.