A method for vaporizing organic materials onto a substrate surface to form a film including providing a quantity of organic material into a vaporization apparatus and actively maintaining the organic material in a first heating region in the vaporization apparatus to be below the vaporization temperature. The method also includes heating a second heating region of the vaporization apparatus above the vaporization temperature of the organic material and metering, at a controlled rate, organic material from the first heating region into the second heating region so that a thin cross section of the organic material is heated at a desired rate-dependent vaporization temperature, whereby organic material vaporizes and forms a film on the substrate surface.