Overhang Insulating Layer Blocks Leakage Current in OLED
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Solution Overview
Problem
Organic light emitting devices suffer from leakage currents flowing along the surface direction of the conductive layer, causing undesired lighting of pixels.
Innovation Solution
A method involving the formation of an overhang structure in the silicon insulating layer, where the lowermost circumference is larger than the uppermost circumference, is implemented to block the leakage current path, comprising steps such as forming a silicon insulating layer, etching to create openings, depositing a conductive layer, and forming organic and upper electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional planar insulating layer structure is used, then the manufacturing process is simple, but leakage current flows along the conductive layer surface causing undesired pixel lighting
Solution Approach 1:
The patent applies asymmetry by creating an overhang structure where the lower circumference of the insulating layer is larger than the upper circumference. This asymmetric geometry blocks the leakage current path that would otherwise flow along the conductive layer surface, preventing undesired pixel lighting while maintaining manufacturing feasibility through controlled etching processes.
Solution Approach 2:
The patent transitions from a conventional two-dimensional planar insulating layer to a three-dimensional overhang structure. By adding vertical dimensionality with the overhanging portion extending over the conductive layer, the structure blocks leakage current paths without requiring additional lateral space or complex multi-layer configurations.
2Reliability
If an overhang structure is formed to block leakage current, then pixel isolation is improved, but the etching process becomes more complex
Solution Approach 1:
The patent applies preliminary action by first forming the insulating layer with the overhang structure through selective etching before depositing the conductive layer. This pre-formed overhang structure serves as a built-in barrier that automatically blocks leakage current paths, eliminating the need for additional isolation steps or complex post-processing to prevent pixel crosstalk.
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
Effectively prevents lighting of undesired pixels by blocking the leakage current path and allows for a simple and controlled etching process to form the overhang structure.
Implementation Method 1
etching the silicon insulating layer (40) to form an opening ranging from an upper surface of the silicon insulating layer (40) to the lower electrode (20) so that an overhang structure having a lowermost circumference that is larger than an uppermost circumference is formed
Implementation Method 2
forming a conductive layer on an upper surface of the lower electrode (20) in the opening (32a, 32b) and on a surface of the insulating layer (40) other than the overhang structure (31)
Implementation Method 3
forming an organic material layer on the conductive layer formed on an upper surface of the lower electrode (20) in the opening (32a, 32b)
Data Source
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AI summary
Disclosed is a method of manufacturing an organic light emitting device, an organic light emitting device manufactured by using the method, and an electronic device including the organic light emitting device. The method includes (a) forming an insulating layer on a lower electrode, (b) etching the insulating layer to form an opening ranging from an upper surface of the insulating layer to the lower electrode so that an overhang structure having a lowermost circumference that is larger than an uppermost circumference is formed, (c) forming a conductive layer on an upper surface of the lower electrode in the opening and a surface of the insulating layer other than the overhang structure, (d) forming an organic material layer on the conductive layer formed on the upper surface of the lower electrode in the opening, and (e) forming an upper electrode on an upper surface of the conductive layer disposed on the upper surface of the insulating layer and an upper surface of the organic material layer.