Method of making organic light emitting devices

A method of making an organic light-emitting device comprising at least one bilayer structure, said method comprising:

• providing at least one first layer comprising at least one cross-linkable organic material and at least one onium salt;
• exposing the first layer to ultra-violet light source to afford a cross-linked first layer;
• and
• disposing at least one second layer on the cross-linked first layer;
• to afford a bilayer structure having an enhanced structural integrity relative to the corresponding bilayer structure in which the first layer is not cross-linked.

An organic light-emitting device comprising at least one bilayer structure, said bilayer structure comprising:

• a cross-linked first layer comprising a cross-linked organic material and at least one photoacid;
• and
• a second layer disposed on the cross-linked first layer;
• wherein the bilayer structure has an enhanced structural integrity relative to the corresponding bilayer structure in which the first layer is not cross-linked.