OLED Red Pixel Life Span via Metal Quinolate Mediator
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Solution Overview
Problem
Full color OLED display devices suffer from reduced color reproducibility due to a shorter afterimage life span of the red pixel region, which degrades overall color reproduction.
Innovation Solution
An intermediate layer comprising metal quinolate and an organic material is interposed between the red emission layer and the electron transport layer in the red pixel region to enhance the life span of the red emission layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional OLED structure is used without an intermediate layer, then the device structure is simple, but the red pixel region has a short afterimage life span which degrades color reproducibility
Solution Approach 1:
An intermediate layer comprising metal quinolate and an organic material is introduced between the red emission layer and the electron transport layer. This intermediate layer acts as a mediator that improves electron injection into the red emission layer, thereby extending the afterimage life span of the red pixel region without fundamentally changing the overall device structure
Solution Approach 2:
The intermediate layer is formed using a composite material system consisting of metal quinolate (such as aluminum quinolate, gallium quinolate, or indium quinolate) combined with an organic material (such as NPB, TCTA, or BCP). This composite structure provides both the electron injection enhancement and structural stability needed to improve red pixel longevity
2Reliability
If the red emission layer is directly connected to the electron transport layer, then the fabrication process is simple, but the color reproducibility is degraded due to short afterimage life span
Solution Approach 1:
The intermediate layer serves as a mediator that improves the interface between the red emission layer and electron transport layer, enhancing electron injection efficiency. This resolves the color reproducibility issue by extending red pixel life span while adding only one additional fabrication step that uses conventional OLED materials and processes
Solution Approach 2:
The intermediate layer modifies the electronic and morphological parameters at the interface between the red emission layer and electron transport layer. By changing the composition and structure of this interface layer, electron injection is improved, thereby extending the operational life span and improving color reproducibility
Data Source
AI summary
An organic light emitting diode and a method of fabricating the same. The organic light emitting diode includes a substrate, a first electrode on the substrate, emission layers on the first electrode including red, green and blue pixel regions, and a second electrode on the emission layers. The organic light emitting diode further includes an electron transport layer on the emission layers, and an intermediate layer formed by co-depositing metal quinolate and an organic material between at least one of the emission layers and the electron transport layer. The intermediate layer inhibits hole transport and increases a life span of the red pixel region.