Recessed Hole Injection Layer for Uniform Luminance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional organic electroluminescence elements using metal compounds in charge injection transport layers suffer from uneven luminance and reduced lifespan due to localized electrical field concentration and current flow, leading to deterioration of the light-emitting layer.
Innovation Solution
A double-sided light-emitter design with a recessed charge injection transport layer, where the upper peripheral edge of the recess is covered by the bank, suppressing electrical field concentration and localized current flow, thereby improving luminescence properties and extending the element's lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a metal compound is used in the charge injection transport layer to improve voltage-current density property and reduce deterioration, then the electrical performance is improved, but electrical field concentration occurs at the upper peripheral edge of the recess causing localized current flow and uneven luminance
Solution Approach 1:
The patent applies local quality by creating a recess in the charge injection transport layer at the peripheral edge region, while maintaining the layer's full thickness in the central region. This local structural modification concentrates the light-emitting function in the recess area and prevents electrical field concentration at the upper peripheral edge, thereby achieving uniform luminance distribution across the light-emitting surface while preserving the metal compound's superior electrical performance
Solution Approach 2:
The patent introduces a vertical dimension change by forming a recess structure that extends downward from the upper surface of the charge injection transport layer. This three-dimensional structural modification allows the light-emitting layer to be positioned at different heights in different regions, creating a stepped configuration that eliminates electrical field concentration at the peripheral edge while maintaining effective charge injection and light emission
2Reliability
If the charge injection transport layer is formed with a recess to suppress electrical field concentration, then uneven luminance is reduced, but the structural complexity of the device increases
Solution Approach 1:
The recess structure is implemented only in the peripheral edge region of the charge injection transport layer, while the central region maintains its original planar structure. This localized modification approach suppresses electrical field concentration at the problematic peripheral edges without requiring complex structural changes throughout the entire device, thereby achieving uniform luminance with minimal increase in structural complexity
Solution Approach 2:
The charge injection transport layer is effectively segmented into two functional regions: a recessed peripheral region that suppresses electrical field concentration and a planar central region that maintains standard charge injection function. This segmentation allows each region to be optimized for its specific function while using relatively simple manufacturing processes
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 effectively reduces uneven luminance and extends the lifespan of the organic electroluminescence element by preventing localized deterioration of the light-emitting layer, enhancing the overall luminescence property and display quality.
Implementation Method 1
The organic EL element is a light-emitter that uses the phenomenon of electroluminescence occurring in organic material
Implementation Method 2
the upper peripheral edge of the recess is covered with a portion of the bank, the electrical field concentration in the vicinity of the upper peripheral edge of the recess is suppressed
Data Source
AI summary
The present disclosure aims to provide a light-emitter having a favorable luminescence property, a light-emitting device having the light-emitter, and a method of manufacturing the light-emitter. Specifically, the light-emitter has the following structure. A hole injection layer and a light-emitting layer are layered between a first electrode and a second electrode which are transparent, and a light-emitting layer exists in an area defined by a bank. Thus, organic EL elements are formed. The hole injection layer has a recess in an upper surface of the area defined by the bank. An upper peripheral edge of the recess in the hole-injection layer is covered with a portion of the bank.