Graphene Diffusion Barrier for OLED Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic electronic devices, such as OLEDs, face degradation due to diffusion of atoms, ions, and molecules, especially at elevated temperatures and under light exposure, leading to instability in performance over time.
Innovation Solution
Incorporating an essentially transparent and electrically conductive graphene layer as a diffusion barrier within the organic electronic device to prevent the diffusion of atoms, ions, and molecules, maintaining the initial composition and performance of the organic layers by utilizing a graphene compound layer with sp2 bonded carbon in a two-dimensional crystal structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If organic layers are doped to improve charge injection and reduce resistivity losses, then device performance is enhanced, but diffusion of dopants occurs at elevated temperatures leading to performance degradation
Solution Approach 1:
An undoped organic layer is introduced as an intermediary barrier between doped organic layers. This intermediate layer prevents direct diffusion of dopants between adjacent doped layers while maintaining electrical connectivity through charge carrier transport, thus preserving doping concentration stability without compromising device performance
Solution Approach 2:
The device structure is segmented into multiple functional layers including doped layers, undoped barrier layers, and emitting units. This segmentation isolates dopant diffusion to specific regions while maintaining overall device functionality through the coordinated operation of separated functional units
2Reliability
If operation temperature is elevated to improve device performance, then charge injection and light emission are enhanced, but diffusion of atoms and molecules increases causing composition changes
Solution Approach 1:
Undoped organic layers serve as thermal diffusion barriers between doped layers. These intermediary layers have lower dopant concentrations that reduce thermal diffusion rates, preventing harmful thermal effects from propagating between functional layers while allowing beneficial charge injection to occur
Solution Approach 2:
The undoped organic layers create an inert environment with respect to dopant diffusion. By providing a region with minimal dopant content between doped layers, these layers act as protective zones that prevent thermal diffusion of dopants even at elevated operating temperatures
3Adaptability or versatility
If multiple light-emitting units are stacked to achieve white light emission, then device versatility and efficiency are improved, but complexity of layer structure and manufacturing increases
Solution Approach 1:
The undoped organic layers serve multiple functions simultaneously: they act as diffusion barriers between doped layers, provide electrical connectivity for charge carrier transport between emitting units, and serve as structural spacers in the stacked configuration. This multi-functionality reduces the need for additional specialized layers, simplifying the overall device architecture
Solution Approach 2:
Multiple light-emitting units are merged into a single stacked device structure with shared electrodes and intermediate undoped layers. This merging approach achieves white light emission through the combination of multiple colored emissions while consolidating functional elements, reducing the need for separate devices and simplifying the overall system
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 graphene layer effectively hampers or prevents the diffusion of dopants and other critical substances, ensuring stable performance and longevity of the organic electronic device even at elevated temperatures and under light exposure, maintaining high transparency and electrical conductivity.
Implementation Method 1
at least one essentially transparent and electrically conductive graphene layer arranged in contact to at least one of the organic layers acting as a diffusion barrier against diffusion of atoms, ions or molecules into or from this organic layer
Implementation Method 2
utilizing a graphene compound layer with sp2 bonded carbon in a two-dimensional crystal structure
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention relates to the field of organic electronic devices (1) with diffusion barriers and to a method to manufacture such organic electronic devices (1) to provide an organic electronic device (1) with excellent performance, which is as stable as possible over time. The organic electronic device (1) with a substrate (2), a first electrode (3) arranged on top of the substrate (2) and a functional layer stack (FLS) arranged on top of the first electrode (3) comprising one or more organic layers (41, 42, 43) and a second electrode (5), wherein the organic electronic device (1) further comprises at least one essentially transparent and electrically conductive graphene layer (6) arranged in contact to at least one of the organic layers (41, 42, 43) acting as a diffusion barrier against diffusion of atoms, ions or molecules into this organic layer (41, 42, 43).