The invention relates to a device for introducing a carrier gas and liquid compounds or a liquid solution into an evaporation chamber, comprising a mixing chamber, including at least:—a first inlet for the admission of said compounds or said solution,—a second inlet for the admission of the carrier gas,—and an outlet connected to an inlet of an injector, so that a mixture of carrier gas and droplets of said compounds or of said solution is periodically injected, through a single injector outlet, into the evaporation chamber.