Patent ID: 7507478

Claim:
An optical stack comprising a sub-stoichiometric layer in direct contact with a stabilizing layer, wherein the sub-stoichiometric layer consists of a homogeneous sub-stoichiometric composition selected from the group consisting of oxides, nitrides and oxynitrides, where the sub-stoichiometric composition comprises at least one element selected from the group consisting of metal elements and semiconductor elements, and the sub-stoichiometric composition further comprises a sub-stoichiometric amount of at least one element selected from the group consisting of oxygen and nitrogen; the stabilizing layer comprises the at least one element selected from the group consisting of metal elements and semiconductor elements, and a stoichiometric amount of the at least one element selected from the group consisting of oxygen and nitrogen; and the sub-stoichiometric layer is from 10 to 100 nm thick and thicker than the stabilizing layer.