a thin - film - transistor organic electroluminescent device comprises : a substrate ; a plurality of stripes of first conductive lines ; a plurality of stripes of second conductive lines , intersecting the first conductive lines ; a plurality of functional elements located at the intersections of the first conductive lines and the second conductive lines , including a transistor having a drain , a source and a gate ; a cathode mounted on the surface of the substrate and connected to the drain ; an anode mounted on the cathode ; and at least one organic electroluminescent medium sandwiched between the cathode and the anode ; wherein the cathode and the first conductive lines are made of the same material .