Light-Emitting Device With Integrated Driving Transistor and Capacitor
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Solution Overview
Problem
Current light-emitting devices face limitations in increasing the degree of integration due to separate driving transistors for controlling current, which complicates the configuration and design of pixel arrays and display devices.
Innovation Solution
The light-emitting device integrates a driving transistor and a capacitor within the device structure, including a multi-quantum well layer, conductive type-doped material layers, and a current blocking layer, allowing for controlled current flow and enhanced integration, with a method of manufacturing that involves forming electrode layers and insulating layers to create a compact, efficient light-emitting device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If separate driving transistors are used for controlling current in light-emitting devices, then current control function is achieved, but device complexity increases and degree of integration is limited
Solution Approach 1:
The patent merges the driving transistor and capacitor functions directly into the light-emitting device structure. The third electrode layer serves as the gate electrode of the driving transistor, while the capacitor is formed between the second electrode layer (cathode) and third electrode layer (gate). This integration eliminates separate driving circuit components, reducing device complexity while enhancing the degree of integration.
Solution Approach 2:
The electrode layers serve multiple functions simultaneously. The third electrode layer functions as both a cathode for current injection and a gate electrode for controlling current flow through the multi-quantum well layer. The second electrode layer serves as both anode and one electrode of the storage capacitor. This multi-functionality reduces the number of components needed.
2Ease of operation
If driving circuit is bonded separately to LED pixel, then active-matrix driving is achieved, but manufacturing complexity increases
Solution Approach 1:
The patent combines the light-emitting pixel and driving circuit into a single integrated structure. The driving transistor is formed within the same device stack as the light-emitting multi-quantum well layer, with the third electrode layer serving as the gate. This eliminates the need for separate bonding processes between driving circuits and LED pixels, significantly reducing manufacturing complexity.
3Manufacturing precision
If current blocking layer is added to control current flow, then current control precision is improved, but device structure becomes more complex
Solution Approach 1:
The third electrode layer (gate) inherently provides current control functionality by controlling the formation of conductive channels in the multi-quantum well layer through voltage application. The gate structure itself serves the dual purpose of current injection (as cathode) and current control (as gate electrode), eliminating the need for separate current blocking layers while maintaining precise current control.
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 integration increases the degree of integration of light-emitting devices, simplifies the configuration of display devices, and allows for controlled brightness and pixel brightness, facilitating easier attachment to backplanes and improved circuit design.
Implementation Method 1
a multi-quantum well (MQW) layer between the first electrode layer and the second and third electrode layers
Implementation Method 2
a first material layer between the first electrode layer and the MQW layer, the first material layer doped with a first conductive type dopant; a second material layer between the second and third electrode layers and the MQW layer, the second material layer doped with a second conductive type dopant
Implementation Method 3
a current blocking layer configured to at least partially block a flow of a current between the second electrode layer and the MQW layer
Implementation Method 4
a gate insulating layer between the third electrode layer and the second material layer
Data Source
AI summary
A light-emitting device includes a first electrode layer; a second electrode layer; a third electrode layer separated from the first and second electrode layers; a multi-quantum well (MQW) layer between the first electrode layer and the second and third electrode layers; a first material layer between the first electrode layer and the MQW layer and doped with a first conductive type dopant; a second material layer between the second and third electrode layers and the MQW layer and doped with a second conductive type dopant; a gate insulating layer between the third electrode layer and the second material layer; and a current blocking layer configured to at least partially block a flow of a current between the second electrode layer and the MQW layer.