OLED Emissive Layer Doping for Efficiency and Lifespan Balance
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Solution Overview
Problem
Existing organic light emitting diodes (OLEDs) face challenges in achieving high luminous efficiency and long luminous lifespan, particularly with metal complex phosphorescent materials that have short commercial lifespans.
Innovation Solution
Incorporating an organic metal compound with a specific structure as a dopant in the emissive layer, combined with (hetero) aryl-amine-based and azine-based hosts, to enhance charge transfer and reduce driving voltage, thereby improving luminous efficiency and lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If phosphorescent material (metal complex) is used to achieve high luminous efficiency, then luminous efficiency is improved, but luminous lifespan deteriorates (short lifespan)
Solution Approach 1:
The patent changes the chemical structure parameters of the phosphorescent dopant by introducing specific ligand structures (Formula 2 and Formula 3) with particular substituent groups (R1-R9). This structural modification optimizes the balance between luminous efficiency and lifespan by adjusting the molecular properties of the metal complex without changing its fundamental phosphorescent mechanism.
Solution Approach 2:
The patent creates a composite emissive layer system combining phosphorescent dopant (metal complex with specific ligands) and host material. This composite structure allows the dopant to provide high luminous efficiency while the host material supports long-term stability and lifespan, resolving the contradiction between efficiency and durability.
2Productivity
If conventional phosphorescent materials are used, then triplet exciton energy is utilized for high luminous efficiency, but commercial lifespan remains short
Solution Approach 1:
The patent modifies the chemical parameters of the phosphorescent material by incorporating specific ligand structures (Formula 2 and Formula 3) with various substituent groups. These parameter changes enhance the stability and durability of the metal complex while maintaining its ability to utilize triplet exciton energy for high luminous efficiency.
Solution Approach 2:
The patent develops an organic metal compound that replaces traditional metal complexes with shorter lifespans. By using organic ligands with specific structures, the material achieves both high efficiency and extended lifespan, making it suitable for commercial applications where durability is critical.
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 results in reduced driving voltage and enhanced luminous efficiency and lifespan of the OLEDs, making them suitable for applications in organic light emitting devices.
Implementation Method 1
Incorporating an organic metal compound with a specific structure as a dopant in the emissive layer, combined with (hetero) aryl-amine-based and azine-based hosts, to enhance charge transfer and reduce driving voltage
Implementation Method 2
An organic light emitting diode (OLED) among a flat display device used widely has come into the spotlight as a display device replacing rapidly a liquid crystal display device (LCD)
Implementation Method 3
phosphorescent material can show high luminous efficiency since it uses triplet exciton energy as well as singlet exciton energy in the luminous process
Data Source
AI summary
The present disclosure relates to an organic light emitting diode (OLED) in which at least one emitting material layer includes a dopant having the following structure of Formula 1 and a (hetero) aryl-amine-based material having with a fluorenyl moiety and/or an azine-based material, and an organic light emitting device including the OLED. The OLED and the organic light emitting device including the host and the dopant can improve their luminous efficiency and luminous lifespan.Ir(LA)m(LB)n [Formula 1]