Encapsulated organic light emitting device

Claim 1

A light emitting device comprising an organic light emitting material sandwiched between first and second electrode, the first electrode contiguous to a transparent substrate and the second electrode contiguous to a protective covering, the second electrode comprising an alkali metal, alkaline earth metal or rare earth metal and the protective covering comprising (a) a first layer of gold, silver, indium, aluminum or a transition metal directly on and in contact with the second electrode, (b) a second layer of dielectric material directly on and in contact with the first layer and selected from the group consisting of silicon nitride, silicon oxide, germanium oxide and zirconium oxide, the second layer having a thickness in the range of 50-500 nanometers, and (c) a third layer of hydrophobic polymer directly on and in contact with the second layer.