LED Current-Blocking Layer via Ion Implantation
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Solution Overview
Problem
Conventional light-emitting diodes (LEDs) face reduced light efficiency due to the upper electrode blocking emitted light, and existing solutions like dielectric layers increase fabrication complexity and damage the light-emitting layer.
Innovation Solution
A current-blocking layer is formed in the upper layer of the LED by implanting ions such as magnesium to create a resistive region, allowing current to flow around the electrode and minimizing light obstruction, while maintaining a planar surface and reducing surface damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a dielectric layer is formed on the light-emitting layer to force current around the electrode, then light efficiency is improved, but fabrication complexity and cost increase
Solution Approach 1:
The patent changes the electrical resistance parameter of the upper layer by implanting ions (such as magnesium, carbon, or silicon) to create a current-blocking layer. This modifies the layer's conductivity to force current flow around the electrode, achieving light efficiency improvement without adding dielectric layers or patterning steps.
Solution Approach 2:
The patent replaces the mechanical/dielectric approach (forming physical dielectric layers and patterns) with an electrical/ionic approach (ion implantation to modify conductivity). This substitution eliminates the need for deposition and patterning equipment while achieving the same current redirection effect.
2Use of energy by moving object
If a dielectric layer is deposited and patterned on the light-emitting layer, then light efficiency is improved, but surface damage occurs reducing crystal quality
Solution Approach 1:
The patent replaces mechanical etching and deposition processes with ion implantation followed by epitaxial regrowth. This substitution eliminates surface damage from etching while achieving current blocking through conductivity modification, thereby preserving crystal quality.
Solution Approach 2:
The patent discards the damaged surface layer through epitaxial regrowth, recovering the crystal structure. The ion implantation creates the current-blocking effect, and subsequent epitaxial growth restores the surface, eliminating damage while maintaining the electrical modification.
3Device complexity
If the upper electrode is positioned directly above the light-emitting layer, then device simplicity is maintained, but light efficiency decreases due to light blocking
Solution Approach 1:
The patent changes the electrical resistance parameter of the upper layer through ion implantation, creating a current-blocking layer that redirects current flow. This allows the electrode to remain in its simple position while improving light efficiency by forcing current to flow around the electrode rather than through the center.
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 approach enhances light efficiency by preventing light blocking from the upper electrode and minimizes surface damage during fabrication, thereby improving the quality and yield of LED devices.
Implementation Method 1
A current-blocking layer is formed in the upper layer to reduce the amount of current flowing through the light-emitting layer
Implementation Method 2
The current blocking layer may be formed by, for example, implanting ions, such as magnesium, carbon, silicon, or other ions, into the upper layer to create a resistive region
Implementation Method 3
The radiative recombination of electron-hole pairs can be used for the generation of electromagnetic radiation (e.g., light) by the electric current in a p-n junction
Data Source
AI summary
A light-emitting diode (LED) device is provided. The LED device has a lower LED layer and an upper LED layer with a light-emitting layer interposed therebetween. A current blocking layer is formed in the upper LED layer such that current passing between an electrode contacting the upper LED layer flows around the current blocking layer. When the current blocking layer is positioned between the electrode and the light-emitting layer, the light emitted by the light-emitting layer is not blocked by the electrode and the light efficiency is increased. The current blocking layer may be formed by converting a portion of the upper LED layer into a resistive region. In an embodiment, ions such as magnesium, carbon, or silicon are implanted into the upper LED layer to form the current blocking layer.