Laser photodissociation of trimethylgallium in the gas phase and on a quartz substrate as studied by multiphoton ionization-time of flight mass spectroscopy

Abstract

UV laser photodissociation of trimethylgallium (TMG) in the gas phase and on a quartz surface at 110 K was studied with multiphoton ionization (MPI)-time of flight mass spectroscopy. A series of ions, Ga(CH 3 ) n + (n=1-3), Ga + , and CH n + (n=1-3), were observed in the photolysis in the gas phase. The dependence of ion signal intensitics on photodissociation/photoionization laser wavelength and on laser power was studied, and its implication in the reaction mechanism is discussed. The parent ion Ga(CH 3 ) 3 + was observed for the first time. Its depletion at ∼215 and ∼220 nm indicates the presence of a metastable species which absorbs light in the ionization step of excited TMG