Flexible OLED Barrier Layers for Moisture Resistance

The patent employs a composite barrier layer structure combining organic and inorganic materials. The barrier layer includes an organic layer (first or second plastic layer) and an inorganic layer (first or second inorganic barrier layer) stacked together, creating a composite structure that leverages the flexibility of organic materials while providing the moisture and oxygen barrier properties of inorganic materials.

The patent implements a nested multi-layer barrier structure where multiple barrier layers are stacked sequentially. The first plastic layer and first inorganic barrier layer form an first barrier structure, while the second plastic layer and second inorganic barrier layer form a second barrier structure. These nested layers create a complex transmission path that effectively blocks moisture and oxygen while maintaining flexibility.

The composite barrier layer structure combining organic and inorganic materials provides both weight reduction (from flexible plastic substrate) and enhanced durability (from the protective barrier against moisture and oxygen). The inorganic barrier layers prevent degradation while the organic layers maintain flexibility and light weight.

The barrier layers are applied beforehand to the flexible substrate to prevent future degradation. The first and second inorganic barrier layers are deposited on the plastic layers before the organic light-emitting layer is formed, creating a protective cushion against moisture and oxygen that prevents degradation before it can occur.

The composite structure of organic and inorganic layers in the barrier layer creates interfacial bonding between layers with different adhesive properties. The organic layer provides good adhesive strength to the plastic substrate, while the inorganic layer provides the moisture barrier, and their interface creates a composite structure that maintains both adhesion and barrier performance.

The patent applies different materials with different properties at different locations in the barrier structure. The organic layers are positioned where adhesive bonding is critical (interface with plastic substrate), while inorganic layers are positioned where moisture blocking is most effective. This local optimization of material properties resolves the contradiction between adhesion and barrier performance.