LED Contact Layer Grading for Lower Schottky Barrier

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Solution Overview

Problem

Current light emitting diode (LED) technologies face challenges in increasing the efficiency of optoelectronic semiconductor components, specifically the ratio of output optical power to supplied electrical power.

Innovation Solution

The design involves an optoelectronic semiconductor component with a first and second semiconductor layer of compound semiconductor materials, featuring a second contact region with a semiconductor contact layer and a metallic contact layer, where the concentration of composition elements varies, and a semiconductor connecting layer with a smaller band gap, reducing the effective Schottky barrier and contact resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional metallic contact layer is directly applied to the second semiconductor layer, then the manufacturing process is simple, but the contact resistance is high and forward voltage is increased

Engineering Contradiction:

Improvecontact resistanceVSAvoidcontact region structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A semiconductor contact layer with graded composition is introduced as an intermediary between the metallic contact layer and the second semiconductor layer. This intermediate layer has a composition that transitions from matching the second semiconductor layer to being more compatible with the metallic contact, thereby reducing contact resistance and forward voltage without excessive structural complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The composition parameters of the semiconductor contact layer are gradually changed from position to position. The layer contains composition elements in varying concentrations, creating a graded structure that optimizes the transition between the semiconductor and metallic layers, reducing Schottky barrier effects and improving electrical contact.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the concentration of composition elements is kept uniform in the contact layer, then the manufacturing process is simpler, but the Schottky barrier effect remains high

Engineering Contradiction:

Improveforward voltageVSAvoidcontact layer fabrication

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The semiconductor contact layer exhibits local quality variations through its graded composition. Different regions of the layer have different concentrations of composition elements, with the composition locally optimized to match either the semiconductor layer or the metallic contact layer, thereby reducing the Schottky barrier effect across the interface.

Inventive Principle:

Principle #3Local quality

3Productivity

If a semiconductor connecting layer with smaller band gap is added, then the efficiency is improved, but the device structure becomes more complex

Engineering Contradiction:

Improveoptical power efficiencyVSAvoidlayer structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The contact region employs a composite structure consisting of the second semiconductor layer, the graded semiconductor contact layer with varying composition, and the metallic contact layer. This composite material approach creates a multi-layer system where each layer contributes specific properties, improving overall efficiency while managing structural complexity.

Inventive Principle:

Principle #40Composite materials

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 enhances the efficiency of the LED by reducing the forward voltage, enabling operation at high currents and improving service life while increasing the output optical power relative to electrical power consumption.

Implementation Method 1

reducing the effective Schottky barrier and contact resistance

Methodology Applied

Scientific EffectSchottky barrier reduction:

Implementation Method 2

When electrons and holes recombine with one another in the region of the pn junction, due, for example, to a corresponding voltage being applied, electromagnetic radiation is generated

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS11764330B2Optoelectronic semiconductor component having a semiconductor contact layer and method for producing the optoelectronic semiconductor component

Publication Date: 2023.09.19 AMS OSRAM INT GMBH

AI summary

In an embodiment, an optoelectronic semiconductor component includes a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, wherein a respective semiconductor material of the first and second semiconductor layers are each a compound semiconductor material including a first, a second and a third composition element, and a second contact region configured to electrically contact the second semiconductor layer, wherein the first semiconductor layer is patterned and arranged over the second semiconductor layer, wherein the second contact region is arranged between patterned regions of the first semiconductor layer, wherein the second contact region comprises a second metallic contact layer and a semiconductor contact layer between the second metallic contact layer and the second semiconductor layer, wherein a semiconductor material of the semiconductor contact layer includes the first, second and third composition elements, and wherein a concentration of the first and second composition elements varies from a position on a side of the second semiconductor layer to a position on a side of the second metallic contact layer.