A nitrogen-containing TCO (Transparent Conductive Oxide) cap composition or layer that may be used as a capping over a TCO layer (such as doped zinc oxide) to provide enhanced thermal, chemical and scratch resistant properties. It may also be used to improve the surface smoothness of the resultant stack. The nitrogen-containing TCO cap composition or layer may be deposited onto a TCO layer, which is deposited on a transparent substrate such as glass using chemical vapor deposition methods. The nitrogen-containing TCO cap compositions or layers are comprised of at least 2 different metal elements with one of them being a Group liA element (i.e., B, Al, Ga, In, Tl, Uut.) along with oxygen and nitrogen.