OLED Emissive Layer Materials for Saturated Color Without Filters
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Solution Overview
Problem
Existing OLEDs face challenges in achieving saturated red, green, and blue colors for full color displays, and white OLEDs often require additional filtering steps to produce these colors, which can be inefficient.
Innovation Solution
The use of specific organometallic compounds, such as (L1-L2)nIr(LA)3−n and (LB)nIr(L3-L4)3−n, as emitters in the emissive layer of OLEDs, combined with a host that includes donor and acceptor groups, to enhance color emission without the need for additional filtering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional white OLEDs use absorption filters to produce saturated colors, then color saturation can be achieved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent extracts and removes the absorption filter components from the OLED structure by directly incorporating phosphorescent emitter molecules that inherently emit saturated colors. This eliminates the need for separate filtering layers while maintaining color saturation performance.
Solution Approach 2:
Instead of using white light emission followed by color filtering (conventional approach), the patent inverts the approach by directly emitting saturated colors through phosphorescent molecules, eliminating the need for filters and simplifying the device structure.
2Manufacturing precision
If additional filtering steps are added to white OLEDs to produce saturated colors, then color quality improves, but manufacturing complexity increases
Solution Approach 1:
The patent removes the filtering steps from the manufacturing process by using phosphorescent emitter molecules that directly produce saturated colors. This simplifies manufacturing while maintaining color quality through molecular design rather than post-processing filters.
3Illumination intensity
If absorption filters are used in OLEDs to produce saturated colors, then color emission can be achieved, but energy efficiency decreases
Solution Approach 1:
The patent converts the previously wasted energy in white light filtering into useful phosphorescent emission. By using phosphorescent emitter molecules that directly emit saturated colors, the system recovers energy that would otherwise be lost in absorption filtering, improving overall energy 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
This approach allows for direct emission of saturated colors, improving the efficiency and reducing the complexity of color production in OLEDs.
Implementation Method 1
OLEDs make use of thin organic films that emit light when voltage is applied across the device
Implementation Method 2
One application for phosphorescent emissive molecules is a full color display
Data Source
AI summary
Provided is an OLED having an anode, a cathode and an organic emissive layer disposed between the anode and the cathode. The emissive layer includes a first host; and a first emitter; wherein the first emitter is selected from the following group: (L1-L2)nIr(LA)3−n and (LB)nIr(L3-L4)3−n; wherein (L1-L2)nIr(LA)3−n isand (LB)nIr(L3-L4)3−n is