OLED Blue Emitter Composite Material Voltage Efficiency
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Solution Overview
Problem
Existing organic light emitting diodes (OLEDs) face limitations in driving voltage, emitting efficiency, color purity, and lifespan, particularly in blue emission.
Innovation Solution
An OLED structure comprising a first and second electrode with a blue emitting material layer containing specific compounds, including an n-type host, a p-type host, and a phosphorescent dopant, optimized to reduce driving voltage, enhance emitting efficiency, and improve color purity and lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional OLED materials are used for blue emission, then the device can operate, but emitting efficiency is limited and lifespan is reduced
Solution Approach 1:
The patent employs a composite emitting material layer comprising multiple compounds (Formula 1, Formula 3, and Formula 5) with specific weight ratios. This composite approach combines the advantages of different materials to simultaneously improve both emitting efficiency and lifespan, resolving the contradiction between these two performance parameters in conventional OLEDs.
Solution Approach 2:
The patent optimizes the weight percentages of the first, second, and third compounds in the emitting material layer, maintaining specific ratios (first compound: 40-60 wt%, second compound: 30-50 wt%, third compound: 10-30 wt%). By precisely controlling these compositional parameters, the patent achieves both high emitting efficiency and extended lifespan.
2Productivity
If blue emission materials are optimized for efficiency, then emitting efficiency improves, but color purity deteriorates
Solution Approach 1:
The patent assigns specific functional roles to different compounds within the emitting material layer: the first compound (Formula 1) provides high emitting efficiency, while the second compound (Formula 3) and third compound (Formula 5) work together to ensure color purity. This local differentiation of material functions allows simultaneous optimization of both efficiency and color purity.
Solution Approach 2:
By creating a composite system with multiple compounds having complementary properties, the patent achieves both high emitting efficiency from the first compound and color purity from the second and third compounds, resolving the trade-off between these properties.
3Use of energy by stationary object
If driving voltage is reduced to improve energy efficiency, then use of energy improves, but emitting efficiency may deteriorate
Solution Approach 1:
The patent optimizes the energy levels and HOMO-LUMO gaps of the compounds in the emitting material layer to enable efficient charge injection and recombination at lower driving voltages. The specific molecular structures in Formulas 1, 3, and 5 are designed to achieve favorable energy alignments that reduce voltage requirements while maintaining high emitting efficiency.
Solution Approach 2:
The composite material system combines compounds with complementary energy level characteristics, enabling efficient charge transport and recombination at reduced driving voltages while maintaining high emitting efficiency, thus resolving the contradiction between energy efficiency and emitting efficiency.
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 effectively reduces driving voltage, increases emitting efficiency, and extends the lifespan of OLEDs while maintaining improved color purity, particularly in blue emission.
Implementation Method 1
The OLED emits light by injecting electrons from a cathode as an electron injection electrode and holes from an anode as a hole injection electrode into an emitting material layer, combining the electrons with the holes, generating an exciton, and transforming the exciton from an excited state to a ground state.
Implementation Method 2
the first blue emitting material layer includes a first compound, a second compound and a third compound... the third compound is represented by Formula 5... each of d1, d2 and d3 is independently an integer of 0 to 4, d4 is an integer of 0 to 3, and d5 is an integer of 0 to 2
Data Source
AI summary
The present invention relates to an organic light emitting diode and an organic light emitting device including the organic light emitting diode. The organic light emitting diode includes a first electrode; a second electrode facing the first electrode; and a first blue emitting material layer including a first compound, a second compound and a third compound and positioned between the first and second electrodes, wherein the first compound is represented by Formula 1, the second compound is represented by Formula 3, and the third compound is represented by Formula 5, and wherein in the first blue emitting material layer, a summation of a weight % of the first compound, a weight % of the second compound and a weight % of the third compound is 100%, and the weight % of each of the first and second compounds is greater than the weight % of the third compound.