Spirobifluorene Delayed Fluorescence Material for OLED Efficiency
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Solution Overview
Problem
Despite various studies on spirobifluorene structure-having compounds for organic electroluminescence elements, comprehensive investigations are lacking, and the usefulness of these compounds as light-emitting materials is not well understood due to the difficulty in synthesizing them and predicting their chemical structure's effectiveness.
Innovation Solution
Development of a delayed fluorescence material with a spirobifluorene structure, represented by a specific general formula, which is used in the light-emitting layer of organic electroluminescence elements to enhance emission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If spirobifluorene structure-having compounds are used as light-emitting materials, then emission efficiency can be improved, but synthesis difficulty increases and comprehensive understanding of their usefulness is lacking
Solution Approach 1:
The patent applies parameter changes by systematically varying the chemical structure parameters of spirobifluorene compounds (different substituents at positions 2, 7, 2', 7') to optimize emission efficiency. By changing molecular weight, substituent types, and structural parameters, the invention achieves high emission efficiency while making the compounds more accessible through established synthesis routes from dibromo- or diiodospirobifluorene intermediates.
2Loss of information
If various spirobifluorene compounds are synthesized and evaluated, then comprehensive understanding of their usefulness improves, but time and resources for investigation increase
Solution Approach 1:
The patent applies segmentation by dividing the comprehensive investigation into systematic categories based on substituent types and positions (2, 7, 2', 7'). This structured approach allows methodical evaluation of different compound classes (electron-donating groups, electron-withdrawing groups, combinations) while organizing the investigation process to avoid redundant studies and accelerate understanding.
Solution Approach 2:
The patent systematically varies key parameters including substituent type (electron-donating vs. electron-withdrawing), substituent position, and molecular weight to establish structure-activity relationships. This parameter-based investigation strategy enables comprehensive understanding to be achieved more efficiently by focusing on how specific parameter changes affect emission efficiency and other useful properties.
3Productivity
If spirobifluorene compounds with optimized emission efficiency are developed, then external quantum efficiency and power efficiency improve, but device complexity may increase
Solution Approach 1:
The patent applies self-service by designing spirobifluorene compounds that inherently possess both high emission efficiency and good charge transport properties within a single material. The molecular structure is optimized to simultaneously achieve high external quantum efficiency through delayed fluorescence mechanisms and adequate charge transport capability, eliminating the need for complex multi-layer device structures with separate host and dopant materials.
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 spirobifluorene-based delayed fluorescence material achieves high emission efficiency in organic electroluminescence elements, surpassing conventional materials by providing a cost-effective solution without the need for rare metals, with improved external quantum efficiency and power efficiency.
Implementation Method 1
the present inventors have found that specific compounds having a spirobifluorene structure have an excellent property as a delayed fluorescence material for organic electroluminescence elements
Data Source
AI summary
A delayed fluorescence material comprising a compound represented by the general formula below. At least one of R1 to R8 represent an electron-donating group and the others represent a hydrogen atom; at least one of R9 to R16 represent an electron-withdrawing group and the others represent a hydrogen atom.