Semi-permeable Pixel Electrode for OLED Optical Resonance
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Solution Overview
Problem
Existing organic light-emitting display devices face challenges in achieving efficient manufacturing processes and optimal display characteristics, particularly in realizing full-color images with optical resonance structures.
Innovation Solution
The organic light-emitting display device incorporates a semi-permeable metal pixel electrode made of a silver alloy, with a multi-layer structure and specific materials for electrodes, along with a method involving multiple mask processes to form a thin film transistor and capacitor layers, ensuring optical resonance and high light efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional manufacturing process is used for organic light-emitting display devices, then the device can be manufactured, but the manufacturing process is complex and display characteristics are not optimal
Solution Approach 1:
The pixel electrode is divided into multiple layers: a lower electrode layer (reflective metal) and an upper electrode layer (transparent conductive material). This segmentation allows each layer to perform its specific function optimally - the lower layer provides reflectivity for optical resonance while the upper layer provides conductivity and protection, resolving the contradiction between manufacturing simplicity and display performance.
Solution Approach 2:
The pixel electrode uses a composite structure combining reflective metal (Al, Ag, or Mo) with transparent conductive materials (ITO, IZO, ZnO, In2O3, IGO, or AZO). This composite material approach enables the electrode to simultaneously achieve high reflectivity for optical resonance and sufficient electrical conductivity, while the etch rate difference between materials facilitates selective etching processes.
2Ease of manufacture
If the pixel electrode is made of transparent conductive material only, then the manufacturing process is simple, but optical efficiency and light efficiency are reduced
Solution Approach 1:
The pixel electrode combines transparent conductive materials with reflective metals in a multi-layer structure. The reflective metal layer (Al, Ag, or Mo) at the bottom provides high reflectivity to enable optical resonance and enhance light efficiency, while the transparent conductive material layer on top maintains electrical conductivity and allows for simple manufacturing processes. This composite approach resolves the contradiction between manufacturing simplicity and optical efficiency.
3Illumination intensity
If the pixel electrode is made of reflective metal only, then optical efficiency is improved, but the electrode is damaged during etching processes
Solution Approach 1:
The pixel electrode is segmented into a lower reflective metal layer and an upper transparent conductive material layer. The transparent conductive material layer serves as a protective overlay that shields the reflective metal layer from damage during subsequent etching processes, while the reflective metal layer maintains its optical efficiency. This segmentation resolves the contradiction between optical efficiency and electrode durability.
Solution Approach 2:
The transparent conductive material layer is deposited beforehand on the reflective metal layer to provide protective cushioning during etching processes. This pre-established protective layer prevents direct exposure of the reflective metal to harsh etching conditions, thereby preserving both the optical efficiency and structural integrity of the pixel electrode.
4Ease of manufacture
If a single-layer pixel electrode is used, then the manufacturing process is simple, but the pixel electrode cannot achieve optical resonance
Solution Approach 1:
The pixel electrode is segmented into multiple layers with distinct materials and functions: a lower reflective metal layer for optical resonance and an upper transparent conductive material layer for conductivity and protection. This multi-layer segmentation enables optical resonance by creating the necessary optical cavity structure while maintaining manufacturing simplicity through sequential deposition and etching processes.
Solution Approach 2:
The pixel electrode employs composite materials with different optical and electrical properties - reflective metals (Al, Ag, Mo) for optical resonance and transparent conductive materials (ITO, IZO, ZnO, In2O3, IGO, AZO) for electrical conductivity. The etch rate difference between these materials enables selective etching, allowing the multi-layer structure to be formed through relatively simple manufacturing processes while achieving optical resonance.
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 configuration simplifies the manufacturing process, enhances optical efficiency, and prevents damage to the pixel electrode during etching, while achieving excellent display characteristics and increased light efficiency through optical resonance.
Implementation Method 1
organic light-emitting display devices have been considered as next generation displays due to their advantages such as light weight, thin thickness, wide viewing angle, fast response speeds, and low power consumption
Implementation Method 2
organic light-emitting display devices for realizing full-color images adopt an optical resonance structure for changing the optical lengths of wavelengths which are emitted from organic emission layers in pixels of different colors
Implementation Method 3
The pixel electrode includes a semi-permeable metal electrically connected to one of the source and drain electrodes... The pixel electrode is a semi-permeable mirror partially receiving and reflecting light emitted from the organic emission layer
Data Source
AI summary
In an organic light-emitting display device and a method of manufacturing the same, the organic light-emitting display device comprises: an active layer of a thin film transistor which includes a semiconductor material, and which is formed on a substrate; a lower electrode of a capacitor which includes a semiconductor material doped with ion impurities, and which is formed on the substrate; a first insulating layer formed on the substrate so as to cover the active layer and the lower electrode; a first gate electrode which is a transparent conductive material, and which is formed on the first insulating layer; a second gate electrode which is a metal, and which is formed on the first gate electrode; an upper electrode of a capacitor which is formed on the first insulating layer and includes a transparent conductive material; source and drain electrodes of a thin film transistor which are electrically connected to the active layer; a pixel electrode formed on the first insulating layer, which is a semi-permeable metal electrically connected to one of the source and drain electrodes; an intermediate layer formed on the pixel electrode and including an organic emission layer; and an opposite electrode facing the pixel electrode with the intermediate layer therebetween.