Abstract: A container for vaporizing a solid material includes a housing having side walls, a bottom wall, and a cover enclosing an interior volume. The cover includes at least one aperture to permit egress of vapor efflux from the housing. A heater heats at least a portion of the housing to vaporize the solid material. A baffle disposed between the cover and the solid material prevents a direct line of sight between the solid material and the aperture(s) and is spaced from the cover to control the flow of vaporized material into a region between the baffle and the cover to promote uniformity of vapor efflux from the aperture(s). The ratio of the interior volume to a volume of the region between the baffle and the cover is at least approximately 20:1. The solid material can be an organic material used to form a layer of an organic light-emitting device.