Diazafluorene OLED Emitter Materials for Low-Voltage Deep Blue Emission
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Solution Overview
Problem
Current OLEDs using existing emitting materials have high driving voltage, low emission efficiency, and short lifespan, necessitating the development of novel emitting materials for improved performance.
Innovation Solution
A novel compound with a diazafluorene core structure is introduced, which can be used as a fluorescent or thermally activated delayed fluorescence host material, providing deep blue emission with high color purity, efficiency, and long lifespan by controlling HOMO and LUMO energy levels and charge balance in the emitting layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If related art emitting materials are used in OLED, then device structure can be maintained, but driving voltage is high and emission efficiency is low
Solution Approach 1:
The patent applies parameter changes by modifying the molecular structure of emitting materials to achieve desired energy levels. Specifically, the compound formulas (1) and (2) with defined substituents (R1-R6, Q, Ar, Y, X1-X8) allow tuning of HOMO and LUMO energy levels to optimize both driving voltage and emission efficiency, resolving the contradiction between these two parameters.
Solution Approach 2:
The patent employs composite materials through the host-guest system where dopant materials with smaller energy band gaps are doped into host emitting material layers. This composite approach enables energy transfer from host to dopant, achieving high emission efficiency while maintaining device structure, thus resolving the contradiction between emission efficiency and structural integrity.
2Duration of action of stationary object
If related art emitting materials are used in OLED, then device structure can be maintained, but lifespan is short
Solution Approach 1:
The patent uses parameter changes by designing compounds with specific molecular structures (formulas 1 and 2) that simultaneously improve lifespan and emission efficiency. The defined substituents and core structures enable optimization of material stability and energy transfer properties, allowing the OLED to maintain high emission efficiency over extended operational periods.
3Reliability
If dopant with smaller energy band gap is doped into emitting material layer, then emission efficiency is improved, but driving voltage increases
Solution Approach 1:
The patent applies parameter changes by carefully selecting dopant materials with specific energy band gaps that are smaller than the host but optimized to minimize driving voltage increase. The compound structures in formulas (1) and (2) with可调 substituents allow precise control of energy levels to achieve the optimal balance between emission efficiency improvement and driving voltage maintenance.
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 novel compound achieves high emitting efficiency, long lifespan, and low driving voltage in OLEDs, enhancing quantum efficiency and color purity while reducing operational voltage.
Implementation Method 1
when the dopant, which has smaller energy band gap and higher emission efficiency than the host and higher, is doped into an emitting material layer, the exciton, which is generated in the host, is transferred into the dopant such that the light with high emission efficiency is provided
Implementation Method 2
The emission of the fluorescent material is derived from a singlet excited state
Data Source
AI summary
The present disclosure provides a compound of following formula and an organic light emitting device and an organic light emitting display device including the compound. The compound of the present disclosure serves as a host or a dopant in an emitting material layer.