Organic EL Element Guest-Host Phosphorescent Layer Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional organic electroluminescent elements face challenges in achieving high emission efficiency and long lifespan while maintaining controlled emission wavelength, with existing phosphorescent materials often exhibiting reduced lifespan and shifted emission wavelengths.
Innovation Solution
An organic electroluminescent element is designed with a light emitting layer containing a guest compound having a specific substructure and a host compound, represented by particular formulas, which together enhance emission efficiency and lifespan, and allow for controlled emission wavelength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional phosphorescent materials are used to improve emission efficiency, then light emission efficiency increases, but emission wavelength shifts and lifespan reduces
Solution Approach 1:
The patent changes the chemical structure parameters of the phosphorescent guest compound by introducing specific substituents (aryl, alkyl, heteroaryl groups) at defined positions of the core structure. This structural parameter modification optimizes both the emission wavelength stability and lifespan while maintaining high emission efficiency through improved molecular stability and controlled energy levels.
Solution Approach 2:
The patent employs a composite light emitting layer combining a host compound and a guest compound with specific structural features. The host-guest system creates a synergistic effect where the host provides structural stability and the guest provides phosphorescent emission, resolving the contradiction between efficiency and lifespan through material composition optimization.
2Loss of energy
If conventional phosphorescent materials are used to improve emission efficiency, then light emission efficiency increases, but emission wavelength control becomes difficult
Solution Approach 1:
The patent systematically modifies structural parameters of the guest compound including substituent types, their positions, and molecular geometry. These parameter changes allow precise tuning of the emission wavelength while maintaining high emission efficiency through optimized phosphorescent properties of the modified core structure.
3Illumination intensity
If high voltage is applied to inorganic electroluminescent elements to achieve light emission, then light emission is achieved, but power consumption increases
Solution Approach 1:
The patent replaces inorganic electroluminescent materials with organic phosphorescent materials that operate at lower voltages. This substitution changes the fundamental mechanism from inorganic band-gap emission to organic phosphorescence, enabling low-power operation while maintaining light emission through the use of triplet excited states.
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 an organic EL element with improved emission efficiency, long lifespan, and controlled emission wavelength, enabling the creation of high-performance illuminators and displays.
Implementation Method 1
an organic EL element, employing phosphorescence through the excited triplet, has been reported by Prinston University
Implementation Method 2
an organic electroluminescent element containing an anode, a cathode and having therebetween a light emitting layer
Data Source
AI summary
An organic electroluminescent element containing an anode and a cathode having therebetween a light emitting layer, wherein the light emitting layer contains a guest compound having a substructure represented by the following Formula (A):wherein Ra represents alkyl, alkenyl, alkynyl, cycloalkyl, aromatic hydrocarbon, aromatic heterocyclic or heterocyclic, Rb and Rc represent hydrogen or a substituent, A1 represents a group of atoms which forms an aromatic hydrocarbon ring or an aromatic heterocycle, M represents Ir or Pt, and a host compound having the following Formula (1):wherein Ra1 represents alkyl, alkenyl, alkynyl, cycloalkyl or heterocyclic, R1, R2 and R5 each represent hydrogen or a substituent, and n1, n2 and n5 each represent 0 to 4.