OLED Emissive Ligand Materials for Saturated RGB and White Light
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Solution Overview
Problem
Existing organic light emitting diodes (OLEDs) struggle to achieve saturated red, green, and blue pixel emissions required for full color displays, and conventional methods for achieving white light emission are inefficient.
Innovation Solution
Development of a compound with a first ligand LA comprising a specific structure coordinated to a metal M, which can be used in an OLED to enhance the emission of specific colors and improve the efficiency of white light production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional white OLED structures are used, then white light emission is achieved, but emission saturation and efficiency are insufficient
Solution Approach 1:
The patent divides the white OLED into separate red, green, and blue emissive layers, each optimized for its specific color emission. This segmentation allows each layer to achieve saturated emission in its respective color while maintaining overall white light output, resolving the contradiction between emission saturation and efficiency.
Solution Approach 2:
The patent applies different organic compounds and materials to different regions (red, green, blue layers) based on their specific emission requirements. Each layer uses materials optimized for its wavelength range, enabling saturated emission in each color region while maintaining high overall efficiency.
2Illumination intensity
If absorption filters are used to produce saturated colors from white backlight, then color display is achieved, but emission efficiency decreases
Solution Approach 1:
The patent extracts the color generation function from passive absorption filtering and implements it through active emission in separate red, green, and blue organic layers. This eliminates the energy loss associated with absorption filters while achieving saturated color emission.
Solution Approach 2:
The patent introduces organic emissive compounds as intermediary materials that directly generate saturated colors through electroluminescence. These compounds act as mediators between electrical input and color output, replacing the inefficient absorption filter approach.
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 compound enhances the ability of OLEDs to produce saturated red, green, and blue pixels, and improves the efficiency of white light emission, meeting industry standards for color displays.
Implementation Method 1
OLEDs make use of thin organic films that emit light when voltage is applied across the device
Data Source
AI summary
A compound having a first ligand LA of Formula Iis provided. In Formula I, moiety A and moiety D are each independently a monocyclic ring or fused polycyclic ring system, wherein the monocyclic ring or each ring of the polycyclic fused ring system is independently a 5-membered to 10-membered carbocyclic or heterocyclic ring. Moiety C is a 5-membered or 6-membered carbocyclic or heterocyclic ring. At least one RC or RD is a substituent R* comprising a carbocyclic or heterocyclic group. Formulations, OLEDs and consumer products containing the compound are also provided.