Fabrication of full-color phosphor screen by electrophoretic deposition combined with photolithography

Electrophoretic deposition was employed to apply a phosphor coating, for use in the fabrication of a full color screen consisting of red (R), green (G), and blue (B) phosphors. Patterned phosphor layers can be fabricated by the electrophoretic deposition, combined with photolithography. For this process, R,G, and B phosphors were deposited on a patterned ITO glass by means of photoresist. The phosphor could be deposited, not on the photoresist surface, but on the patterned conductive substrate, since the photoresist has insulating properties. Conventional photolithographic conditions cannot be used for electrophoretic deposition due to the fact that the photoresist is soluble in the alcoholic solvent, which is used after baking. A suspension of the insoluble photoresist was obtained by optimizing the baking temperature. Patterned color screens, prepared by electrophoretic deposition combined with photolithography were studied using SEM and photo luminescence spectroscopy.