Red Micro-LED Current Barrier Structure for Sidewall Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Micro-LEDs, particularly red light-emitting devices, face issues with low external quantum efficiency and non-uniform color gradation due to increased sidewall defects and higher surface recombination velocity as they miniaturize, leading to carrier leakage and reduced luminance at low currents.
Innovation Solution
A red light-emitting semiconductor device with a current concentration structure incorporating a strain-induced layer and high-resistance layers formed by segregation, which acts as a barrier to carrier movement, concentrating current in areas of low resistance and reducing surface recombination velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the light-emitting device chip is miniaturized to reduce size, then the device can be used in micro-LED displays with thinness and flexibility, but the external quantum efficiency decreases due to increased sidewall defects and higher surface recombination velocity
Solution Approach 1:
The patent applies local quality by introducing a current concentration structure with specific local properties (strain-induced layer and high-resistance layers) at critical locations (between contact layer and confinement layer) to address the localized problem of carrier leakage at sidewalls, while maintaining the overall miniaturized chip structure
Solution Approach 2:
The current concentration structure acts as an intermediary element between the contact layer and confinement layer, mediating carrier transport by providing a controlled path that prevents direct leakage to sidewalls while maintaining efficient current injection into the active region
2Length of moving object
If the chip size is reduced, then the device achieves micro-LED dimensions suitable for high-resolution displays, but the ratio of sidewall area to chip area increases, leading to more dangling bonds and carrier capture by sidewall defects
Solution Approach 1:
The current concentration structure serves as an intermediary barrier that intercepts and redirects carriers before they can reach the sidewall defects, effectively isolating the harmful sidewall region from the carrier flow path
Solution Approach 2:
The patent implements preliminary action by establishing the current concentration structure in advance to pre-control carrier paths, preventing carrier leakage to sidewalls before the harmful interaction can occur
3Illumination intensity
If AlGalnP material is used for red light emission, then the desired red wavelength is achieved, but the surface recombination velocity is approximately 10 times higher than InGaN, causing increased initial carrier loss
Solution Approach 1:
The patent converts the harmful high surface recombination velocity into a beneficial effect by using the strain-induced layer to create controlled segregation of Al and Ga elements, forming high-resistance layers that actually reduce carrier loss by providing selective barrier properties
4Ease of manufacture
If dry or wet etching is performed for dicing to separate the chip, then the chip can be isolated and mounted, but the sidewall damage rate increases
Solution Approach 1:
The current concentration structure with high-resistance layers serves as a beforehand cushioning mechanism that protects the sidewall region from etching damage by providing a structural buffer zone that reduces the impact of mechanical stress and chemical exposure during dicing
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
The solution enhances current density and improves low-current characteristics by suppressing carrier leakage to the sidewall, increasing internal radiative recombination and maintaining luminance, thus addressing the inefficiencies in micro-LEDs.
Implementation Method 1
A red light-emitting semiconductor device is provided, which includes a strain induced layer; and high-resistance layers that contact the strain induced layer and are distributed separately from each other to form a current barrier
Implementation Method 2
high-resistance layers that contact the strain induced layer and are distributed separately from each other to form a current barrier
Implementation Method 3
an active layer disposed on the first conductive confinement layer; a second conductive confinement layer disposed on the active layer
Data Source
AI summary
The present disclosure relates to a red-light-emitting semiconductor light-emitting device, which is applicable to a technical field related to a display device, for example, can be used in a display device, and to a method for manufacturing same. The present disclosure may comprise: a substrate; a buffer layer located on the substrate; a first conductive contact layer located on the buffer layer; a first conductive constraint layer located on the first conductive contact layer; an active layer located on the first conductive constraint layer; a second conductive constraint layer located on the active layer; and a current concentration structure located on at least one side of between the first conductive contact layer and the first conductive constraint layer and between the second conductive contact layer and the second conductive constraint layer. In this case, the current concentration structure may include: a lattice strain induction layer; and a high resistance layer which is in contact with the lattice strain induction layer, separated from the lattice strain induction layer, and distributed to form a current barrier.