Hole Injection Layer Composition for OLED Voltage Stability
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Solution Overview
Problem
Existing organic semiconductor materials and electronic devices suffer from poor operating voltage stability over time, necessitating improved compounds for semiconductor layers to enhance device performance.
Innovation Solution
Incorporation of a compound of formula (I) in the hole injection layer, combined with a specific anode layer structure comprising multiple sub-layers, including a first anode sub-layer with a work function between 4 and 6 eV and a transparent conductive oxide sub-layer, to optimize hole injection and electron transport.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional organic semiconductor materials are used, then device structure can be kept simple, but operating voltage stability over time deteriorates
Solution Approach 1:
The anode layer is segmented into multiple sub-layers (first anode sub-layer with metal having work function 4-6 eV, second anode sub-layer with transparent conductive oxide, and optionally third anode sub-layer) to achieve better operating voltage stability. This segmentation allows each sub-layer to perform specific functions: the metal sub-layer provides appropriate work function for hole injection, while the transparent conductive oxide sub-layer ensures optical transparency and electrical conductivity.
Solution Approach 2:
The patent employs composite material structure in the anode layer by combining different materials (metal with specific work function, transparent conductive oxide) to create a multi-sublayer architecture. This composite approach enables the anode to simultaneously provide optimal electrical properties for hole injection and optical transparency, resolving the contradiction between reliability improvement and structural complexity.
2Reliability
If compound of formula (I) is incorporated in hole injection layer, then operating voltage stability improves, but manufacturing process complexity increases
Solution Approach 1:
The patent introduces compounds of formula (I) with specific molecular structures containing electron-withdrawing groups (such as cyano, carbonyl, or trifluoromethyl groups) to modify the hole injection layer's properties. By changing the chemical parameters of the compound (introducing specific functional groups and structural features), the hole injection efficiency and operating voltage stability are improved while maintaining compatibility with existing manufacturing processes.
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 organic electronic devices with superior operating voltage stability and performance over time, surpassing conventional devices in terms of efficiency and longevity.
Implementation Method 1
the first anode sub-layer comprises a first metal having a work function in the range of ≥ 4 and ≤ 6 eV
Implementation Method 2
the second anode sub-layer comprises a transparent conductive oxide
Implementation Method 3
The holes and electrons recombine in the EML to generate excitons. When the excitons drop from an excited state to a ground state, light is emitted.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present invention relates to a compound of formula (I) and an organic electronic device comprising a semiconductor layer which comprises a compound of formula (I).