Dual Emission OLED Cathode Selective Deposition

Instead of using a metal mask to block metal deposition where the cathode should not be formed, the patent inverts the approach by using an organic auxiliary layer to selectively attract metal vapor deposition. The auxiliary layer is applied only in regions where the cathode electrode should be formed, and the metal vapor is deposited without a mask, allowing the metal to selectively adhere to the auxiliary layer regions.

The patent introduces an organic auxiliary layer as an intermediary substance between the metal vapor source and the substrate. This auxiliary layer acts as a mediator that selectively attracts and binds metal vapor molecules, enabling patterned cathode formation without requiring a physical metal mask. The auxiliary layer is subsequently removed, leaving the desired electrode pattern.

The patent introduces an organic intermediate layer as a mediator between the cathode electrode and the organic emitting layer. This intermediate layer serves as a buffer that prevents direct contact between the electrode and the emitting layer, thereby avoiding exciton quenching while maintaining a compact device structure. The intermediate layer is subsequently removed, but it has already fulfilled its protective function during the deposition process.

The patent performs a preliminary action by forming the cathode electrode pattern before removing the auxiliary layer. The auxiliary layer is applied, metal vapor is deposited selectively on it, and then the auxiliary layer is removed - all before forming the final device structure. This preliminary patterning action allows subsequent layers to be formed without requiring continuous mask usage.

The patent inverts the conventional masking approach by eliminating the need for multiple metal masks. Instead of using masks to define where electrodes should NOT be formed, the method uses organic auxiliary layers to define where electrodes SHOULD be formed. This allows all electrode patterns to be formed in a single metal vapor deposition step without sequential masking operations.

The organic auxiliary layer serves multiple functions: it acts as a pattern definition layer, a deposition template, and a temporary protective layer. By applying different auxiliary layers to different regions, the method can simultaneously define patterns for multiple electrodes (first electrode, second electrode, third electrode) in a single metal deposition process, eliminating the need for multiple separate patterning steps.