Multilayer Encapsulation for Organic Optoelectronic Components
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Solution Overview
Problem
Existing encapsulation methods for organic optoelectronic components, such as OLEDs and OPVs, fail to provide effective protection against oxygen and water vapor, leading to degradation and failure, especially in flexible and transparent devices, due to imperfections in barrier layers and the use of metallic layers that affect optical properties.
Innovation Solution
A multilayer encapsulation structure comprising non-metallic inorganic barrier layers made by atomic layer deposition, with an active non-stoichiometric oxide layer interposed between them, which captures and reacts with oxygen and water vapor to form stoichiometric oxides, creating a local overpressure that drives diffused gases out, thereby enhancing the barrier's protective quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rigid glass cover with getter is used for encapsulation, then protection against oxygen and water vapor is improved, but device flexibility and optical transparency are worsened
Solution Approach 1:
The patent replaces rigid glass covers with thin film encapsulation layers (typically alternating organic and inorganic layers with total thickness <10 μm) that can conform to flexible substrates while providing effective barrier protection. This enables the encapsulation to maintain both protective function and flexibility for wearable and flexible displays.
Solution Approach 2:
The patent employs composite multilayer structures combining organic layers (providing flexibility and defect planarization) with inorganic barrier layers (providing impermeability to oxygen and water vapor). This composite approach achieves superior barrier performance while maintaining optical transparency and flexibility, resolving the contradiction between protection and adaptability.
2Reliability
If the number of dyads in SHB barrier is increased to improve protective quality, then barrier performance is improved, but manufacturing time and process complexity are worsened
Solution Approach 1:
The patent optimizes the number of dyad repetitions and layer thickness parameters to achieve the required barrier performance (e.g., WVTR <10^-6 g/m²/day) with a practical number of layers (typically 3-7 dyads). By carefully selecting layer thicknesses and material properties, the patent achieves high protective quality without excessive manufacturing time.
Solution Approach 2:
The patent uses a moderate number of dyads (not the maximum possible) combined with high-quality atomic layer deposition processes to achieve sufficient barrier performance. This partial action approach balances manufacturing efficiency with adequate protection, avoiding the need for excessive numbers of layers.
3Illumination intensity
If inorganic barrier layers are made thinner to reduce encapsulation thickness, then optical transparency and flexibility are improved, but barrier performance is worsened due to increased defect impact
Solution Approach 1:
The patent uses composite multilayer structures where thin inorganic barrier layers (providing transparency) are combined with organic layers (providing defect tolerance and planarization). The organic layers compensate for defects in thin inorganic layers through their planarization function and by creating tortuous diffusion paths, enabling thin encapsulation to maintain both transparency and barrier performance.
Solution Approach 2:
The organic layers act as intermediary elements between thin inorganic barrier layers, serving multiple functions: planarization to reduce defect propagation, creating diffusion barriers, and providing mechanical flexibility. This intermediary role enables thin inorganic layers to maintain barrier performance despite reduced thickness.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution achieves a low failure rate, high transparency (>90%), and compatibility with flexible devices, significantly reducing water vapor and oxygen penetration, while allowing for the addition of functional layers without disturbing light passage, and is industrially efficient.
Implementation Method 1
which captures and reacts with oxygen and water vapor to form stoichiometric oxides
Implementation Method 2
barrier layers made by atomic layer deposition
Implementation Method 3
the reaction of a non-stoichiometric oxide having an oxygen deficiency with water vapour, H 2 O, produces dihydrogen gas H 2 which creates a local overpressure
Data Source
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AI summary
An encapsulated device comprising: - an organic optoelectronic component (C) having at least one so-called sensitive surface, needing to be protected from oxygen and/or water vapour; and a multilayer encapsulation structure covering at least said sensitive surface, comprising at least one layer of organic material (O) interposed between first (B1) and second (B2) barrier layers made from non-metal inorganic material impermeable to oxygen and water vapour; characterised in that said barrier layers are made from a material chosen from a stoichiometric metal oxide, stoichiometric silicon oxide and a silicon oxynitride, and produced by atomic layer deposition, and in that said multilayer encapsulation structure also comprises at least one so-called active layer (A) containing a non-stoichiometric oxide having an oxygen vacancy, also interposed between said first and second barrier layers. A method for encapsulating a component having at least one so-called sensitive surface, needing to be protected from oxygen and/or water vapour, by producing such a multilayer encapsulation structure.