Semiconductor Light-Emitting Device Guard Ring Doping
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Solution Overview
Problem
Conventional light-emitting diodes experience decreased light-emitting efficiency due to non-radiative recombination caused by lattice dislocations on the side walls of the epitaxial structure, especially when the device volume is reduced.
Innovation Solution
The semiconductor light-emitting device features an epitaxial structure with a main light-extraction surface and a lower surface, where the doping material concentration is higher in a second portion than in a first portion, and the epitaxial structure is designed to minimize the side surface area through a specific geometry and doping distribution, allowing for improved light extraction and reduced non-radiative recombination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the volume of the light-emitting diode is decreased, then the device size is reduced, but the light-emitting efficiency is decreased due to increased influence of non-radiative recombination from lattice dislocations on the side wall
Solution Approach 1:
The patent applies local quality by creating a guard ring structure with different doping concentration than the main active region. The guard ring portion has higher doping concentration, which modifies the local electrical properties to reduce carrier leakage and non-radiative recombination at the side wall interface, thereby maintaining high light-emitting efficiency in miniaturized devices.
Solution Approach 2:
The patent segments the epitaxial structure into distinct functional regions: a central active region for light emission and a surrounding guard ring region for electrical confinement. This segmentation allows independent optimization of each region's properties, enabling the guard ring to compensate for side wall effects while the active region maintains its light-emitting function.
2Quantity of substance
If the side surface area of the epitaxial structure is increased, then more electrical current can flow through the device, but non-radiative recombination increases due to lattice dislocations on the side wall
Solution Approach 1:
The guard ring acts as an intermediary structure between the central active region and the device substrate. It provides a transition zone with modified doping concentration that prevents direct interaction between high-current-density regions and the problematic side wall interface, thereby reducing non-radiative recombination while still allowing sufficient current flow.
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 design enhances light-emitting efficiency by reducing non-radiative recombination and increasing the percentage of electrical current flowing through the device, resulting in higher luminous intensity and improved light extraction.
Implementation Method 1
electrical holes and electrons recombine in the active layer 10b to release light with a peak wavelength
Data Source
AI summary
A semiconductor light-emitting device comprises an epitaxial structure comprising an main light-extraction surface, a lower surface opposite to the main light-extraction surface, a side surface connecting the main light-extraction surface and the lower surface, a first portion and a second portion between the main light-extraction surface and the first portion, wherein a concentration of a doping material in the second portion is higher than that of the doping material in the first portion and, in a cross-sectional view, the second portion comprises a first width near the main light-extraction surface and second width near the lower surface, and the first width is smaller than the second width.