OLED Internal Extraction Layer Non-Planar Interface

The patent introduces a non-planar interface with curved or textured surfaces between layers of the OLED structure. This curvature disrupts the planar geometry that causes total internal reflection, allowing trapped light to escape. The curved interface changes the angle of light propagation, enabling evanescent waves to couple out and improve light extraction efficiency without fundamentally redesigning the entire device architecture.

The patent modifies the refractive index parameters by introducing intermediate extraction layers with refractive indices that differ from adjacent layers. This parameter change creates gradual refractive index transitions rather than abrupt changes, reducing internal reflection at interfaces. The non-planar interface geometry is also optimized with specific curvature radii and texture parameters to maximize light outcoupling while maintaining manufacturability.

The patent divides the extraction function into multiple segments: a non-planar interface layer with specific curvature, intermediate extraction layers with different refractive indices, and potentially multiple textured layers. Each segment performs a specific function in the light extraction process, allowing optimization of each individual component while maintaining overall system manageability and manufacturability.

The patent introduces intermediate extraction layers that act as mediators between the organic emissive layer and the substrate. These intermediate layers have refractive indices that are intermediate between the adjacent layers, creating a gradient transition that reduces internal reflection. The non-planar interface serves as a mediator that transforms trapped evanescent waves into propagating light modes, enabling efficient energy transfer without requiring complete structural redesign.