A one touch valve for activating fluid flow between an inlet conduit and an outlet conduit is disclosed. The device and method can prevent changes in image density and contrast, which are caused by repeated displaying over long periods of time and changes in environment, by employing accurate electric current detection, due to the following operations. The silicon precursor can be flowed into the process chamber with the flow of the dopant precursor or separately from the flow of the dopant precursor. , metals or metal oxides andor alloys of such materials are dispersed into ionic liquids to create a heat transfer fluid.