Organic Emission Layer With Mixed-Host Compounds for Lower Voltage
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Solution Overview
Problem
Existing organic electronic devices face challenges in achieving high efficiency, long lifespan, and reduced driving voltage due to issues with intermolecular interactions and material stability, particularly in the emission layer, which affect color purity and luminous efficiency.
Innovation Solution
Incorporating compounds represented by Formulas 1, 2, and 3 in the emission layer to optimize energy levels, T1 values, and intrinsic material properties, such as mobility and interfacial characteristics, thereby improving charge balance and reducing driving voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single material is used as an emission material, then the device structure is simple, but color purity deteriorates and luminous efficiency reduces
Solution Approach 1:
The patent employs a host/dopant composite material system where a host material and dopant material are combined in the emission layer. The dopant material (with smaller energy band gap) receives excitons from the host material through energy transfer, enabling the host to emit light at the dopant's wavelength. This composite approach achieves high color purity and luminous efficiency while maintaining manageable device complexity.
2Use of energy by moving object
If efficiency is increased to reduce driving voltage, then Joule heating decreases and lifespan extends, but material stability must be optimized
Solution Approach 1:
The patent optimizes multiple material parameters simultaneously including energy levels, T1 values (triplet state lifetimes), charge mobility, and interfacial characteristics. By carefully selecting and adjusting these parameters for both host and dopant materials, the system achieves high efficiency with reduced Joule heating while maintaining excellent material stability and device lifespan.
3Reliability
If a host/dopant system is used to improve color purity and luminous efficiency, then energy transfer occurs but the emission wavelength shifts to the dopant region
Solution Approach 1:
The patent applies local quality by having different materials perform different functions within the emission layer. The host material provides the primary exciton generation and energy transfer capability, while the dopant material provides the specific emission wavelength and high radiative efficiency. This functional differentiation allows the system to achieve both high color purity and controlled emission wavelength by selecting materials with complementary properties.
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 compounds enhance emission efficiency and extend the device's lifetime by optimizing the organic layer's properties, leading to improved performance and stability.
Implementation Method 1
when a small amount of a dopant having a smaller energy band gap than that of a host forming the emission layer is mixed into the emission layer, excitons generated in the emission layer are transferred to the dopant, thereby enabling light emission with high efficiency
Implementation Method 2
organic electroluminescence refers to a phenomenon in which electrical energy is converted into light energy by an organic material
Data Source
Figure 1~2
Figure 3
AI summary
The present invention provides an organic electronic device comprising a first electrode, a second electrode, and an organic layer between the first and second electrodes, and an electronic apparatus comprising the same. By using a mixture of the compounds of Formula 1 to Formula 3 of the present invention as a mixed-host in the organic layer, the driving voltage of an organic electronic device can be reduced, and the luminous efficiency and lifespan of an organic electronic device can be improved.