Organic Light Emitting Device Charge Balance via Segmented Layers
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Solution Overview
Problem
Existing organic light emitting devices face challenges in achieving a balance between low driving voltage and long service life, with current materials either reducing service life when used in hole injection or hole transporting layers or increasing driving voltage when used in electron transporting layers.
Innovation Solution
Incorporating a compound represented by Chemical Formula 1 as a hole injection or hole transporting layer and a compound represented by Chemical Formula 2 as an electron transporting layer, which provides high hole mobility and thermal stability respectively, to establish charge balance and improve efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a compound with high hole mobility is used in the hole injection or hole transporting layer, then the driving voltage is decreased, but the service life is reduced
Solution Approach 1:
The device is divided into distinct functional layers: a hole injection layer or hole transporting layer using Compound 1 for low driving voltage, and an electron transporting layer using Compound 2 for long service life. This segmentation allows each layer to be optimized for its specific function without compromising the other.
Solution Approach 2:
The patent employs a composite material system where Compound 1 (with high hole mobility and appropriate HOMO level) is combined with Compound 2 (with excellent thermal stability and electron transporting capability). This composite approach enables simultaneous achievement of low driving voltage and long service life by leveraging the complementary strengths of both compounds.
2Duration of action of stationary object
If a compound with excellent thermal stability is used in the electron transporting layer, then the service life is improved, but the driving voltage is increased
Solution Approach 1:
The device structure separates the functions of voltage reduction and service life extension into different layers. The electron transporting layer using Compound 2 is specifically designed for thermal stability and service life, while the hole injection/transporting layer handles the voltage characteristic.
Solution Approach 2:
By combining Compound 2 (excellent thermal stability) with Compound 1 (high hole mobility), the patent creates a composite material system where the thermal stability of Compound 2 ensures long service life while Compound 1 compensates for any increase in driving voltage through its superior hole transporting capability.
3Duration of action of stationary object
If conventional materials are used in the hole injection or hole transporting layer, then the service life is maintained, but the driving voltage is increased
Solution Approach 1:
The patent changes the key parameter of hole mobility by introducing Compound 1 with significantly higher hole mobility than conventional materials. This parameter change enables lower driving voltage while the layered structure with Compound 2 maintains service life.
Solution Approach 2:
The composite material system combines the high hole mobility of Compound 1 with the thermal stability of Compound 2, achieving a performance profile that surpasses conventional materials while maintaining service life through the synergistic interaction between the two compounds.
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 results in an organic light emitting device with low driving voltage and long service life, while also enhancing light emitting efficiency.
Implementation Method 1
an organic material layer including a compound represented by Chemical Formula 1 between the first electrode and the light emitting layer and an organic material layer including a compound represented by Chemical Formula 2 between the second electrode and the light emitting layer
Implementation Method 2
When a voltage is applied to an organic light emitting device having the structure, electrons and holes injected from the two electrodes combine with each other in the organic thin film to make a pair, and then, emit light while being extinguished
Data Source
AI summary
The present specification relates to an organic light emitting device.