LED Transparent Conductive Layer Segmentation for Current Crowding
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Solution Overview
Problem
Conventional light-emitting diodes (LEDs) suffer from current crowding and non-uniform light emission due to poor current spreading, particularly in the p-type semiconductor, leading to reduced efficiency and luminous efficiency.
Innovation Solution
A light-emitting device structure featuring a transparent conductive layer divided into blocks by a trench, with a connecting layer electrically connecting these blocks, and a first conductivity type contact layer with higher conductivity than the semiconductor layer, forming multiple parallel-connected diodes to distribute current evenly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional single electrode structure is used, then the device structure is simple, but current crowding occurs and light emission is non-uniform
Solution Approach 1:
The transparent conductive layer is divided into multiple independent blocks by trenches, transforming a single electrode structure into multiple segmented electrodes. This segmentation enables current to flow through multiple parallel paths, distributing current evenly across the active layer and eliminating current crowding at the center region.
2Manufacturing precision
If the transparent conductive layer is divided into blocks by trenches, then current spreading is improved, but the device structure becomes more complex
Solution Approach 1:
A connecting layer is introduced as an intermediary element to electrically connect the separated transparent conductive blocks. This connecting layer serves as a mediator that maintains electrical continuity between blocks while allowing the trenches to physically separate them, thus achieving both current distribution and structural integrity.
3Manufacturing precision
If the conductivity of the contact layer is increased, then current flow is improved, but material selection and fabrication become more constrained
Solution Approach 1:
The conductivity parameter of the first conductivity type contact layer is specifically increased to be higher than that of the first conductivity type semiconductor layer. This parameter change optimizes current flow from the electrode into the semiconductor, reducing contact resistance and improving overall device efficiency.
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 addresses current crowding and achieves uniform light emission and high luminous efficiency by ensuring equal current flow through multiple paths, enhancing the overall performance of the LED.
Implementation Method 1
a first conductivity type contact layer between the substrate and the first conductivity type semiconductor layer, wherein the conductivity of the first conductivity type contact layer is greater than the conductivity of the first conductivity type semiconductor layer
Implementation Method 2
a connecting layer electrically connecting the two blocks of the transparent conductive layer
Implementation Method 3
The theory for a light-emitting diode (LED) to emit light is that when a forward voltage power is applied to a p-n junction, the electrons are driven from the n-type semiconductor and the holes are driven from the p-type semiconductor, and these carriers are combined in the active layer to emit light
Data Source
AI summary
A light-emitting device is disclosed and comprises: a substrate; a light-emitting stack comprising a first conductivity type semiconductor layer, an active layer over the first conductivity type semiconductor layer, and a second conductivity type semiconductor layer over the active layer; a transparent conductive layer over the a light-emitting stack; a first trench dividing the transparent conductive layer into a first block and a second block; a connecting layer electrically connecting the two blocks of the transparent conductive layer; a first conductivity type contact layer between the substrate and the first conductivity type semiconductor layer, wherein the conductivity of the first conductivity type contact layer is greater than the conductivity of the first conductivity type semiconductor layer.