Organic Light-Emitting Array Bank Structure for Current Leakage
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Solution Overview
Problem
Conventional organic light-emitting arrays experience lateral current leakage between sub-pixels due to the thin organic layer being provided over the entire array area, leading to inefficient current flow and potential color mixing.
Innovation Solution
The organic light-emitting array is designed with a bank having a positively tapered portion overlapping the emission portion and an inversely tapered portion not overlapping the emission portion, causing the organic layer to be structurally disconnected between sub-pixels, preventing lateral current leakage without the need for a separate deposition mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a thin organic layer is provided over the entire array area in a tandem type configuration, then the device structure is simplified and manufacturing is easier, but lateral current leakage occurs between neighboring sub-pixels
Solution Approach 1:
The organic layer is segmented into discrete portions over each sub-pixel through the bank structure, creating physical separation between sub-pixels. The bank divides the continuous organic layer into isolated segments, preventing lateral current flow while maintaining the tandem configuration benefits.
Solution Approach 2:
The bank acts as an intermediary structure between the organic layer and the substrate, physically blocking the organic layer from forming continuous paths between sub-pixels. This intermediary element prevents harmful lateral current leakage without requiring changes to the organic layer deposition process.
2Reliability
If the organic layer is disconnected between sub-pixels, then lateral current leakage is prevented, but the device complexity increases due to asymmetric bank structure
Solution Approach 1:
The bank is designed with asymmetric geometry, having different heights or profiles on opposite sides. This asymmetry creates natural discontinuities in the organic layer deposition, causing the organic material to form separate portions over each sub-pixel without requiring complex additional structures or 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
This configuration effectively prevents lateral current leakage and allows for independent operation of each sub-pixel, reducing color mixing and enhancing the overall performance of the organic light-emitting display device.
Implementation Method 1
electrons and holes are respectively injected into the organic emission layer from the anode and the cathode, and excitons are produced in the organic emission layer via combination of the electrons and holes. Then, when the produced excitons fall down or move from the excited state to the ground state, light is generated from the organic light-emitting element.
Data Source
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AI summary
Disclosed are an organic light-emitting array and an organic light-emitting display device using the organic light-emitting array. The organic light-emitting array includes a substrate (100) having a plurality of sub-pixels (SP), each sub-pixel (SP) including an emission portion and a non-emission portion adjacent the emission portion; a first electrode (111) provided on at least the emission portion and provided on a portion of the non-emission portion for each sub-pixel (SP); a bank (112) provided in the non-emission portion and having a positively tapered portion configured to overlap a portion of the first electrode (111) and a negatively tapered portion configured so as not to overlap the first electrode (111); an organic layer (113) provided on the first electrode (111) and the bank (112); and a second electrode (114) disposed on the organic layer (113) over the plurality of sub-pixels (SP).