OLED Hybrid Connecting Layer for Balanced Carrier Transport
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Solution Overview
Problem
The hybrid connecting layer in OLED devices formed through alternating solution and vacuum thermal evaporation processes struggles to balance carrier transport, leading to unbalanced sub-pixel colors and reduced efficiency and lifetime.
Innovation Solution
Incorporating a hybrid connecting layer formed by a first host material with higher hole mobility and a second host material with higher electron mobility, disposed between functional layers formed through different processes, ensuring balanced carrier transport and improved interface properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hybrid connecting layer is added to improve efficiency and lifetime of vacuum thermal evaporation formed layers, then efficiency and lifetime are improved, but carrier transport balance deteriorates causing color imbalance in sub-pixels
Solution Approach 1:
The patent applies local quality by creating different regions within the hybrid connecting layer with distinct material compositions. The layer includes a first region with materials optimized for hole transport and a second region with materials optimized for electron transport, allowing each region to perform its specific function while maintaining overall carrier balance
Solution Approach 2:
The patent uses composite materials by combining multiple organic compounds with different transport characteristics in the hybrid connecting layer. This includes mixing materials with high hole mobility with materials with high electron mobility to create a balanced interface that transports both carriers effectively
2Adaptability or versatility
If different materials are used at two sides of an interface for solution and vacuum thermal evaporation processes, then process compatibility is improved, but interface properties deteriorate affecting light emitting layer functions
Solution Approach 1:
The patent introduces the hybrid connecting layer as an intermediary between the solution process formed layers and vacuum thermal evaporation process formed layers. This intermediate layer acts as a buffer that is compatible with both processes while ensuring proper interface properties for carrier transport
Solution Approach 2:
The patent applies parameter changes by carefully selecting and adjusting material properties such as HOMO and LUMO energy levels, mobility ratios, and triplet energy values in the hybrid connecting layer to optimize both process compatibility and interface performance
3Productivity
If a hybrid connecting layer is used to transport both electrons and holes, then carrier transport capability is improved, but material selection difficulty increases making it hard to balance carriers
Solution Approach 1:
The patent segments the hybrid connecting layer into distinct functional regions - a first region for hole transport and a second region for electron transport. This segmentation simplifies material selection by allowing independent optimization of each region rather than requiring a single material to perform both functions
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
This approach enhances the OLED's efficiency, extends its lifetime, and reduces operating voltage by effectively managing carrier transport across sub-pixels, preventing color imbalance.
Implementation Method 1
the first host material has a hole mobility greater than its electron mobility
Implementation Method 2
the second host material has an electron mobility greater than its hole mobility
Implementation Method 3
a vacuum thermal evaporation (VTE) process
Data Source
AI summary
The OLED device according to this disclosure at least includes a first electrode, a second electrode and an organic functional layer disposed between the first electrode and the second electrode. The organic functional layer at least includes a first part functional layer formed through a first process, a second part functional layer formed through a second process, and a hybrid connecting layer disposed between the first part functional layer and the second part functional layer. The hybrid connecting layer is formed by using at least a first host material and a second host material. The first host material has a hole mobility greater than its electron mobility, and the second host material has an electron mobility greater than its hole mobility.