Inorganic graded barrier film and methods for their manufacture

A graded barrier film comprising a layered structure, wherein said layered structure comprises:

• a first layer comprising a metal oxide or metal nitride;
• a second intermediate layer comprising alternating layers of a metal nitride and metal oxynitride or alternating layers of a metal oxide and metal oxynitride which is arranged on said first layer;
• and
• a third layer comprising a metal oxide or metal nitride, which is arranged on said second intermediate layer;
• wherein the first layer and the third layer has a thickness up to 60 nm;
• wherein the metal oxide, metal nitride and metal oxynitride comprise a metal which is reactive towards moisture and/or oxygen;
• wherein the vapor permeation rate of the graded barrier film is 10−2 g/m2/day or less at 60° C. and 90% relative humidity;
• and
• wherein the metal of the metal oxide, metal nitride and metal oxynitride is the same.