Organic Light-Emitting Display Panel Electron Injection Optimization
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Solution Overview
Problem
Conventional organic light-emitting diodes suffer from insufficient electron injection and mobility, leading to a decrease in light-emitting efficiency due to the deviation of electron recombination centers from the light-emitting layer.
Innovation Solution
An organic light-emitting display panel design incorporating a specific structure with an anode, cathode, and organic functional layer, including a first and second electron transmission layer with alkaline earth or rare earth metal elements, where the work functions and molecular orbitals are optimized to enhance electron injection and mobility, and prevent dopant diffusion to improve light-emitting efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional organic light-emitting diode structure is used, then device simplicity is maintained, but electron injection and mobility are insufficient causing recombination center deviation
Solution Approach 1:
The organic functional layer is segmented into multiple distinct layers: electron injection layer, first electron transmission layer, organic light-emitting layer, second electron transmission layer, and hole transmission layer. Each layer has specific thickness ranges and material compositions optimized for its function, enabling improved electron injection and mobility while maintaining manageable structural complexity through functional specialization.
Solution Approach 2:
The patent employs composite material structures where each layer contains specific organic compounds with tailored properties. For example, the electron injection layer uses compounds like Alq3 or BCP with specific HOMO/LUMO energy levels, while the light-emitting layer uses emitters like Ir(III) or Pt(II) complexes coordinated with cyclometalating ligands. These composite material designs optimize electron transport and recombination processes.
2Reliability
If electron transmission layers with alkaline earth or rare earth metal elements are added, then electron mobility is improved, but device structure complexity increases
Solution Approach 1:
Alkaline earth metal elements (Mg, Ca, Sr, Ba) or rare earth metal elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) are selectively incorporated into specific layers (electron injection layer and first electron transmission layer) where they provide optimal electron transport properties. This localized use of specialized materials improves electron mobility without requiring all layers to be complex, as each layer has its own optimized composition.
Solution Approach 2:
The patent optimizes the thickness parameters of each layer to control electron transport efficiency. The electron injection layer is designed with thickness of 0.1-10 nm, first electron transmission layer with 10-50 nm, and second electron transmission layer with 10-100 nm. By adjusting these thickness parameters along with material composition, the patent achieves improved electron mobility while controlling the overall device structure.
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 optimized structure improves electron injection and mobility, reduces potential barriers, and enhances light-emitting efficiency by ensuring electrons do not accumulate at interfaces, thereby increasing the response speed and light output of the organic light-emitting display panel.
Implementation Method 1
improve the injection and mobility of electrons in an organic light-emitting diode
Implementation Method 2
improve the injection and mobility of electrons
Implementation Method 3
a work function φ1 of the electron injection layer and a work function φ2 of the cathode satisfy: φ1≥φ2-3.0 eV
Implementation Method 4
The organic light-emitting diode emits light through a light-emitting layer disposed between an anode and a cathode under an electric field applied between the anode and the cathode
Implementation Method 5
prevent dopant diffusion to improve light-emitting efficiency
Data Source
AI summary
Provided are an organic light-emitting display panel and a display device. The organic light-emitting display includes an array substrate and organic light-emitting components each having anode, cathode and organic functional layer. The organic functional layer includes an organic light-emitting layer, a first and second electron transmission layer and an electron injection layer. The first electron transmission layer and electron injection layer include a first dopant containing an alkaline earth metal element or a rare earth metal element. A work function φ1 of the electron injection layer and a work function φ2 of the cathode satisfy: φ1<φ2, and the work function φ1 of the electron injection layer and a work function φ3 of the first dopant satisfy: φ1≥φ3. LUMO1 and LUMO2 satisfy: |LUMO1−LUMO2|<0.18 eV.