Grooved Insulation in Organic Light-Emitting Elements for Leakage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic light-emitting elements face issues with leakage currents between charge generation layers and upper electrodes, leading to reduced luminance and inefficiencies due to thick organic films and microcavity effects, which are not effectively addressed by prior art techniques.
Innovation Solution
The proposed solution involves forming at least one organic layer between the charge generation layer and the upper electrode within a groove in the insulating layer, using a differently coating method to enhance thickness and suppress leakage currents, while maintaining a microcavity structure for efficient light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the thickness of the organic film is increased to enhance light emission efficiency by microcavity effect, then light emission efficiency is improved, but leakage current between charge generation layer and upper electrode increases
Solution Approach 1:
The patent divides the organic film into multiple separate layers (first organic layer, second organic layer, third organic layer) with the charge generation layer positioned between them. This segmentation allows the organic film to achieve sufficient total thickness for microcavity effect while creating discontinuities that block leakage current paths between the charge generation layer and upper electrode.
Solution Approach 2:
The patent applies different functional properties to different regions of the device. The organic layers have high thickness in light-emitting regions to enhance microcavity effect, while the charge generation layer and its associated organic layers create localized high-resistance regions that suppress leakage current. This local differentiation of thickness and material properties resolves the contradiction between overall efficiency and localized leakage.
2Productivity
If a charge generation layer is provided between light-emitting layers to improve power consumption, then light emission efficiency is improved, but leakage current between pixels increases
Solution Approach 1:
The patent introduces an insulating layer as an intermediary barrier between adjacent pixels. This insulating layer with its groove structure acts as a mediator that prevents charge carriers from migrating between pixels through the charge generation layer, thereby eliminating leakage current between pixels while preserving the charge generation layer's function of improving light emission efficiency within each pixel.
3Loss of energy
If the organic film thickness is reduced to suppress leakage current, then leakage current is suppressed, but light emission efficiency by microcavity effect decreases
Solution Approach 1:
The patent resolves the thickness contradiction by transitioning from a single-dimensional thickness parameter to a multi-dimensional layered structure. By stacking multiple organic layers with the charge generation layer in between, the system achieves sufficient optical path length (sum of layer thicknesses) for microcavity effect while maintaining localized thin regions and discontinuities that suppress leakage current. This dimensional transformation allows simultaneous optimization of both parameters.
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
This approach effectively suppresses leakage currents and reduces driving voltage, enhancing light emission efficiency and luminance by maintaining a microcavity effect, thus improving power consumption and performance.
Implementation Method 1
By injecting electrons and holes from the pair of electrodes, excitons of the luminescent organic compound in the organic compound layer are generated, and the organic light-emitting element emits light when the excitons return to the ground state
Implementation Method 2
the thickness between the light-emitting layer of the first light-emitting unit and the light-emitting layer of the second light-emitting unit is set larger than the thickness between the first light-emitting layer and the first electrode, which can increase the light-emitting efficiency by the microcavity effect
Data Source
AI summary
An organic light-emitting element includes a first element having, on a substrate, a first lower electrode, a first light-emitting layer, a charge generation layer, a second light-emitting layer, and an upper electrode in this order, and an insulating layer covering an end of the first lower electrode, wherein the first element has one or more organic layers between the first lower electrode and the charge generation layer, and has one or more organic layers between the charge generation layer and the upper electrode, the insulating layer has a groove on a surface that is in contact with the organic layer disposed between the first lower electrode and the charge generation layer, and at least one of the organic layers disposed between the charge generation layer and the upper electrode is formed in the groove.