WOxNy Anode Layer for OLED Dark Spot Suppression
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Solution Overview
Problem
Organic light-emitting devices face issues with dark spots due to particle generation during anode patterning, which can be mitigated by forming a thick organic layer, but this increases the driving voltage.
Innovation Solution
An anode layer with a WOxNy structure (2.2≦x≦2.6, 0.22≦y≦0.26) is formed using N2 plasma treatment, allowing for a thicker anode without increasing the driving voltage, and including a metal such as silver, aluminum, or molybdenum, with a common anode layer for red, green, and blue sub-pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick organic layer is formed on the anode to suppress dark spots, then dark spot generation is reduced, but driving voltage increases
Solution Approach 1:
The patent changes the chemical composition parameters of the anode material by forming WOxNy through N2 plasma treatment, transforming pure WO3 into a nitrogen-containing compound. This parameter change improves hole injection efficiency and conductivity, allowing the anode to function effectively without requiring a thick organic layer, thus suppressing dark spots while maintaining low driving voltage
Solution Approach 2:
The patent creates a composite anode material WOxNy by combining tungsten oxide (WO3) with nitrogen through plasma treatment. This composite material exhibits superior electrical properties and hole injection characteristics compared to pure WO3, resolving the contradiction between reliability and power requirements
2Ease of operation
If anode patterning is performed to facilitate hole injection, then hole injection is improved, but particle generation occurs causing dark spots
Solution Approach 1:
The patent extracts the patterning step from the manufacturing process by using a common unpatterned anode layer for all sub-pixels. The hole injection efficiency is achieved through the material composition (WOxNy) rather than geometric patterning, thereby eliminating particle generation from the etching process
Solution Approach 2:
The patent replaces the mechanical/chemical etching process with a material-based solution. Instead of physically patterning the anode through etching (which generates particles), the patent uses N2 plasma treatment to modify the WO3 material properties, achieving hole injection efficiency without mechanical intervention
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 N2 plasma-treated WOxNy anode layer provides improved conductivity and hole injection characteristics, reducing the need for patterning and maintaining low driving voltage, while preventing dark spots and allowing for optical distance adjustment.
Implementation Method 1
performing an N2 plasma treatment on the WO3 thin layer to form an anode layer including WOxNy
Data Source
AI summary
An organic light-emitting device including a substrate, an anode layer on the substrate, the anode layer including WOxNy (2.2≦x≦2.6 and 0.22≦y≦0.26), an emission structure layer on the anode layer, and a cathode layer on the emission structure layer.