Hexadentate OLED Emitters for Saturated Phosphorescent Colors
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Solution Overview
Problem
Current organic light-emitting diode (OLED) technologies face challenges in achieving saturated colors, particularly in red, green, and blue emissions, which are essential for full-color displays, and there is a need for materials that can efficiently emit light from both singlet and triplet states to enhance performance.
Innovation Solution
A compound comprising a hexadentate ligand coordinated to metals like iridium, rhodium, or osmium is used in an OLED structure, which enables efficient phosphorescent emission, potentially improving color saturation and overall performance by utilizing the compound in an organic layer within the OLED.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional OLED materials are used, then device structure is simple, but color saturation is insufficient
Solution Approach 1:
The patent modifies the chemical structure of organic emissive materials by introducing specific molecular designs that enable both singlet and triplet state emission. This changes the photophysical parameters of the material to achieve saturated red, green, and blue emissions while maintaining a relatively simple OLED device structure.
Solution Approach 2:
The invention employs composite emissive materials that combine multiple functional moieties within a single molecular structure, enabling simultaneous utilization of singlet and triplet excitons for light emission. This composite approach achieves color saturation without requiring complex multi-layer device architectures.
2Use of energy by moving object
If only singlet state emission is utilized, then device structure is simple, but light emission efficiency is low
Solution Approach 1:
The patent designs organic emissive materials with specific photophysical properties that enable efficient radiative decay from both singlet and triplet excited states. This parameter change in the material's emission mechanism increases light emission efficiency by utilizing previously wasted triplet excitons.
Solution Approach 2:
The invention creates a continuous emission process by enabling both singlet and triplet states to contribute to light output. This continuous utilization of different exciton types maintains high emission efficiency throughout device operation without requiring complex switching mechanisms.
3Use of energy by moving object
If phosphorescent materials are used, then light emission efficiency improves, but achieving saturated colors becomes difficult
Solution Approach 1:
The patent adjusts the photophysical parameters of organic emissive materials to achieve a balance between phosphorescent emission efficiency and color saturation. By modifying molecular structures and energy level configurations, the invention enables saturated red, green, and blue emissions while maintaining efficient utilization of triplet states.
Solution Approach 2:
The invention applies specific molecular design strategies to different emissive layers (red, green, blue) to optimize both efficiency and color saturation locally. Each emissive material is tailored with specific structural features that enhance its particular color output while maintaining high light emission 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 use of this compound in OLEDs enhances light emission efficiency, potentially leading to improved color accuracy and performance by allowing emission from both singlet and triplet states, addressing the limitations of existing OLED technologies.
Implementation Method 1
A compound comprising a hexadentate ligand of Formula I coordinated to a metal selected from the group consisting of iridium, rhodium, and osmium... enables efficient phosphorescent emission, potentially improving color saturation and overall performance by utilizing the compound in an organic layer within the OLED
Data Source
AI summary
A compound comprising a hexadentate ligand of Formula I coordinated to a metal selected from the group consisting of iridium, rhodium, and osmium;whereinrings A, B, C, D, E, and F are independently a 5-membered or 6-membered heteroaryl ring, or a 6-membered aryl ring;T1, T2, T3, T4, T5, and T6 are independently selected from C or N, wherein two to four of T1 to T6 are C, and two to four of T1 to T6 are N;Z1, Z2, Z3, and Z4 are independently selected from C or N, wherein if Z1 and Z2 are each N then T1 is a carbene carbon and two of T2 to T6 are N;Y1 and Y2 are independently selected from the group consisting of CR, SiR, B, or N;W1-W7 are independently selected from the group consisting of a direct bond, BR, BRR′, NR, PR, O, S, Se, C═X, S═O, SO2, CR, CRR′, SiRR′, GeRR′, alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof;wherein X is selected from the group consisting of O, S, Se, NR′, and CR″R′″;RA to RF independently represent mono to the maximum allowable substitution, or no substitution;each R, R′, R″, R′″, and RA to RF is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, boryl, arylalkyl, alkoxy, aryloxy, amino, silyl, germyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, selenyl, and combinations thereof, and any two adjacent substituents R, R′, R″, R′″, and RA to RF are optionally joined to form a fused ring.