OLED Color Filter Layer Layout for Residual Alkali Reliability
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Solution Overview
Problem
Organic light-emitting devices with on-chip color filters face reliability issues due to the presence of residual components from the developing solution, which are not thermally decomposed during the lower temperature formation process, leading to degradation over time.
Innovation Solution
The organic light-emitting device is designed with an insulating layer and color filters where the surfaces facing the organic light-emitting elements are flush, and the concentration of organic alkali in the color filter layer is limited to less than 108.2 ng/cm², ensuring minimal residual organic alkali remains, thereby enhancing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an on-chip color filter is formed at low temperature to match the organic light-emitting element's heat resistance, then the organic light-emitting element can be manufactured, but residual developing solution components remain and deteriorate reliability
Solution Approach 1:
A heat treatment step is performed before forming the color filter to preliminarily remove residual components from the organic light-emitting element. This preliminary action prevents contamination of the color filter layer and ensures high reliability while maintaining low-temperature manufacturing compatibility.
Solution Approach 2:
Residual components (organic alkali) are extracted and removed from the organic light-emitting element through heat treatment before color filter formation. This extraction eliminates the harmful residues that would otherwise remain trapped in the low-temperature-formed color filter, resolving the reliability issue.
2Temperature
If the color filter is formed at low temperature, then compatibility with organic light-emitting element is achieved, but residual organic alkali remains in the color filter layer
Solution Approach 1:
Heat treatment is applied before color filter formation to preliminarily remove organic alkali residues. This preliminary removal reduces the baseline contamination level, ensuring that even at low formation temperatures, the final residual organic alkali concentration remains below 108.2 ng/cm².
Solution Approach 2:
The concentration of organic alkali is controlled by changing the heat treatment parameters (temperature, time) before color filter formation. By optimizing these parameters, the residual organic alkali is reduced to acceptable levels while maintaining low-temperature processing compatibility.
3Temperature
If residual components from developing solution remain, then low-temperature formation is maintained, but device reliability deteriorates under high-temperature and high-humidity conditions
Solution Approach 1:
A heat treatment step is performed before color filter formation to preliminarily remove residual components. This preliminary action eliminates the source of reliability deterioration, allowing the device to maintain high reliability even under high-temperature and high-humidity operating conditions while keeping the formation temperature low.
Solution Approach 2:
The heat treatment performs a preliminary anti-action by removing residual organic alkali that would otherwise cause reliability deterioration. This preventive removal counteracts the harmful effects before they can manifest during device operation under harsh conditions.
Data Source
AI summary
The present disclosure relates to an organic light-emitting device including an insulating layer, an organic light-emitting element disposed on the main surface of the insulating layer, and a color filter layer covering the organic light-emitting element and including a first color filter that passes light with a first wavelength and a second color filter that passes light with a second wavelength different from the first wavelength, wherein the concentration of an organic alkali having a nitrogen atom and a hydroxy group contained in the color filter layer is less than 108.2 ng/cm2.