Light-Emitting Device Auxiliary Layers Triplet Energy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light-emitting devices face challenges in achieving high quantum efficiency, low driving voltage, and long lifespan due to interfacial degradation and inefficient charge transport.
Innovation Solution
A light-emitting device structure is proposed, featuring a first electrode, a second electrode, and an interlayer with a hole transport region. The interlayer includes a first auxiliary layer with a first compound having a lowest excitation triplet energy level between 1.60 eV and 1.80 eV, and a second auxiliary layer with a hole-transporting compound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional hole transport region structure is used, then the device structure is simple, but interfacial degradation occurs and quantum efficiency is reduced
Solution Approach 1:
The hole transport region is divided into multiple auxiliary layers (first auxiliary layer, second auxiliary layer, third auxiliary layer) with different compounds, each having specific triplet energy levels. This segmentation allows optimization of charge transport and exciton management at different interfaces, preventing interfacial degradation while maintaining manageable device complexity through systematic layer design.
Solution Approach 2:
Each auxiliary layer is assigned specific local properties: the first auxiliary layer has T1 between 1.60-1.80 eV, the second has T1 between 1.80-2.00 eV, and the third has T1 between 2.00-2.20 eV. This local quality differentiation optimizes exciton confinement and charge transport at specific locations within the hole transport region, improving reliability without requiring complete structural redesign.
2Productivity
If standard charge transport materials are used, then the device is easy to manufacture, but driving voltage remains high and quantum efficiency is limited
Solution Approach 1:
The patent systematically changes the triplet energy level parameter (T1) across different auxiliary layers, creating a gradient from 1.60-1.80 eV in the first layer to 1.80-2.00 eV in the second layer, and 2.00-2.20 eV in the third layer. This parameter optimization enables better exciton confinement and charge transport efficiency, improving quantum efficiency while the improved charge transport reduces the driving voltage required for operation.
Solution Approach 2:
The hole transport region uses composite material structure with multiple compounds having different triplet energy levels arranged in specific layers. This composite approach allows simultaneous optimization of multiple functions: exciton confinement, charge transport, and voltage control, achieving high quantum efficiency without requiring excessive driving voltage.
3Reliability
If the hole transport region lacks multiple auxiliary layers, then the device structure is simpler, but charge transport efficiency is reduced
Solution Approach 1:
The hole transport region is segmented into three auxiliary layers, each with progressively higher triplet energy levels. This segmentation creates optimized pathways for charge transport and exciton management, improving reliability through systematic functional division while maintaining reasonable device complexity through consistent layer design patterns.
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 configuration reduces interfacial degradation, enhances charge transport, and results in a light-emitting device with improved quantum efficiency, reduced driving voltage, and extended lifespan.
Implementation Method 1
a lowest excitation triplet energy level (T1) of the first compound may be equal to or greater than 1.60 eV and less than or equal to 1.80 eV
Implementation Method 2
Carriers, such as holes and electrons, recombine in the emission layer to produce excitons. These excitons transition from an excited state to a ground state to thereby generate light.
Data Source
AI summary
A light-emitting device and an electronic apparatus including the same are provided.