OLED Array Substrate Storage Capacitor Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-resolution OLED devices face challenges with insufficient storage capacitance and high leakage current due to the limited space for increasing the aspect ratio of thin film transistors, which affects the stability of pixel voltage and grayscale display.
Innovation Solution
The array substrate of the OLED device incorporates a conductive layer and an insulating layer between the thin film transistor and the organic light-emitting diode, forming a capacitor that enhances storage capacitance and reduces leakage current by using a dual-gate structure for the thin film transistor and a micro-cavity structure for the organic light-emitting diode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the pixel density is increased to achieve high resolution, then the display quality is improved, but the storage capacitance of each pixel becomes insufficient
Solution Approach 1:
The patent merges the storage capacitor with the driving transistor by using the transistor's gate electrode as one plate of the capacitor and forming the other plate beneath the organic light-emitting diode. This integration allows the storage function to be combined with the driving function within the same pixel structure, effectively utilizing space while maintaining sufficient storage capacitance even at high pixel densities
Solution Approach 2:
The patent extends the capacitor structure into the vertical dimension by placing the second electrode beneath the organic light-emitting diode and connecting it to the gate electrode through an insulating layer. This three-dimensional arrangement increases the effective capacitance without occupying additional lateral space, thereby resolving the contradiction between high resolution and sufficient storage capacitance
2Measurement precision
If the pixel area is reduced to increase pixel density, then the resolution is improved, but the leakage current increases
Solution Approach 1:
By integrating the storage capacitor with the driving transistor, the patent reduces the total pixel area required while maintaining adequate storage capacitance. This merged structure prevents the need to further reduce individual component sizes, thereby controlling leakage current even at high pixel densities
Solution Approach 2:
The patent optimizes the capacitance value by adjusting the area and positioning of the capacitor electrodes within the integrated structure. By carefully controlling the capacitor parameters (area, distance between electrodes), the storage capacitance is maximized within the constrained pixel area, which helps maintain stable pixel voltage and reduce leakage current effects
3Quantity of substance
If the aspect ratio of the thin film transistor is increased to provide sufficient storage capacitance, then the storage capacitance is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent combines the storage capacitor structure with the driving transistor structure, using shared components (gate electrode, insulating layers) to fulfill both driving and storage functions. This merger eliminates the need for separate capacitor structures, thereby providing sufficient storage capacitance without increasing device complexity or manufacturing difficulty
Solution Approach 2:
The integrated structure serves multiple functions: the gate electrode acts as both the control electrode for the transistor and one plate of the storage capacitor, while the insulating layer serves as both the transistor gate dielectric and the capacitor dielectric. This multi-functionality reduces the overall device complexity while achieving the required storage capacitance
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 effectively increases storage capacitance and reduces leakage current, improving the display quality of high PPI OLED devices by stabilizing pixel voltage and enhancing luminous efficiency.
Implementation Method 1
the first electrode of the organic light-emitting diode, the insulating layer and the conductive layer form a capacitor
Implementation Method 2
an organic light-emitting diode and a first thin film transistor for controlling the organic light-emitting diode
Data Source
AI summary
An array substrate of an organic light-emitting display device, a fabrication method thereof and an organic light-emitting display device are provided. The array substrate comprises a plurality of pixel units arranged in array, wherein, at least one of the pixel units includes: an organic light-emitting diode (40) and a first thin film transistor (20) for controlling the organic light-emitting diode (40) which are formed on a base substrate (10), wherein, the organic light-emitting diode (40) includes a first electrode (107), a second electrode (110) and a light-emitting layer (109) located between the first electrode (107) and the second electrode (110), the first electrode (107) of the organic light-emitting diode (40) being connected with a drain electrode (104) of the first thin film transistor (20); and a conductive layer (111) and an insulating layer (112) formed between the first thin film transistor (20) and the organic light-emitting diode (40), wherein, the first electrode (107) of the organic light-emitting diode (40), the insulating layer (111) and the conductive layer (112) form a capacitor, and the conductive layer (111) is connected with a first gate electrode (100) of the first thin film transistor (20). The array substrate of the organic light-emitting display device, the fabrication method thereof and the organic light-emitting display device can effectively increase a storage capacitance value of a pixel unit, so as to improve display quality.