Cathode Oxide Removal for OLED Reliability
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Solution Overview
Problem
The reliability and lifespan of organic light emitting displays are reduced due to oxidation at the interface between electrodes during the deposition of cathode electrodes in inverted organic light emitting diodes.
Innovation Solution
A method involving the formation of a transistor on a substrate, followed by a cathode electrode connected to the transistor, a bank layer with an opening, removal of the natural oxide layer using argon plasma, an insulating buffer layer, and subsequent formation of an organic light emitting layer and anode electrode, which prevents oxidation and enhances electron injection efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cathode electrode is deposited in inverted organic light emitting diode, then electrode connection is achieved, but oxidation occurs at the electrode interface reducing reliability and lifespan
Solution Approach 1:
The patent applies preliminary action by removing the natural oxide layer from the cathode electrode surface before depositing the organic light emitting layer. This is achieved through plasma treatment or chemical etching processes that clean the electrode surface in advance, preventing oxidation from compromising the interface between the electrode and organic layers, thereby improving device reliability and lifespan
Solution Approach 2:
The patent employs inert atmosphere by conducting the deposition of organic light emitting layers in a vacuum or inert gas environment (such as nitrogen or argon). This prevents oxidation at the electrode interface during the manufacturing process, maintaining the integrity of the cathode electrode surface and enhancing the overall reliability and lifespan of the organic light emitting display
2Ease of manufacture
If natural oxide layer is present on cathode electrode, then electrode formation is simplified, but electron injection efficiency is reduced
Solution Approach 1:
The patent applies preliminary action by removing the natural oxide layer from the cathode electrode surface before depositing the organic light emitting layer. This is achieved through plasma treatment or chemical etching processes that clean the electrode surface in advance, preventing oxidation from compromising the interface between the electrode and organic layers, thereby improving device reliability and lifespan
Solution Approach 2:
The patent changes the surface parameters of the cathode electrode by controlling the oxide layer thickness through plasma treatment duration and power. By optimizing these parameters, the surface is prepared to have minimal oxidation that would hinder electron injection, while maintaining ease of manufacture through controlled processing conditions
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 method improves the reliability and lifespan of organic light emitting displays by preventing cathode electrode oxidation and increasing electron injection efficiency, thereby enhancing the overall performance of the display.
Implementation Method 1
removal of the natural oxide layer on the cathode electrode
Data Source
AI summary
A method of manufacturing an organic light emitting display includes: forming a transistor on a substrate; forming a cathode electrode on the transistor to be connected to a source or a drain of the transistor; forming a bank layer having an opening on the cathode electrode; allowing a natural oxide layer to form on the cathode electrode; removing the natural oxide layer from the cathode electrode; forming an insulating buffer layer on the cathode electrode; forming an organic light emitting layer on the insulating buffer layer; and forming an anode electrode on the organic light emitting layer.