Thermal-Electrical Structure for LED Current Spreading and Heat Dissipation

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Solution Overview

Problem

Photoelectrical elements, such as LEDs, face issues with current spreading and heat dissipation, leading to reduced luminous efficiency and increased temperature-related recombination rate problems.

Innovation Solution

A thermal-electrical structure is integrated into the conductive structure of the photoelectrical element, utilizing a transparent conductive layer and metal pads with nano-scaled thermal-electrical materials like Bi2Te3, CeAl2, or SiGe to facilitate thermal-electrical conversion and improve current spreading and heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a current spreading layer and extension electrodes are added to improve current spreading, then current distribution is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvecurrent spreadingVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the current spreading function from the traditional current spreading layer and extension electrodes, and integrates it into the substrate itself by forming a conductive type region directly in the semiconductor layer. This eliminates the need for separate current spreading layers and extension electrodes, simplifying the overall structure while maintaining effective current distribution.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the substrate and current spreading function into a single integrated structure. The conductive type region is formed directly within the semiconductor layer of the substrate, combining the mechanical support function of the substrate with the electrical current spreading function, thereby reducing the number of discrete components.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If the light emitting layer temperature is kept low to maintain high recombination rate and luminous efficiency, then luminous efficiency is improved, but heat dissipation capability must be enhanced

Engineering Contradiction:

Improveluminous efficiencyVSAvoidheat dissipation

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent applies local quality by creating a specific thermal-electrical structure at the critical heat generation location (light emitting layer and electrode pad area). The conductive type region with different conductivity type and conductivity is strategically positioned to provide localized heat dissipation enhancement without affecting the overall light emitting characteristics of the device.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent replaces traditional thermal conduction-based heat dissipation structures with a thermal-electrical conversion structure. The conductive type region converts thermal energy into electrical energy through the thermoelectric effect, providing active heat dissipation that simultaneously generates useful electrical current, thereby more effectively maintaining low operating temperature.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If electrode pad area is increased to reduce current density and improve current spreading, then current distribution is improved, but device area and complexity increase

Engineering Contradiction:

Improvecurrent distributionVSAvoiddevice area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent segments the current spreading function across multiple regions within the semiconductor layer through the conductive type region. Instead of requiring a single large electrode pad, the current is distributed through segmented conductive paths formed by the conductive type region, achieving effective current spreading with compact device footprint.

Inventive Principle:

Principle #1Segmentation

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 thermal-electrical structure effectively converts thermal energy to electrical energy, enhancing current spreading and heat dissipation, thereby improving the efficiency and performance of the photoelectrical element by reducing temperature-related recombination and current crowding issues.

Implementation Method 1

the thermal-electrical structure effectively converts thermal energy to electrical energy

Methodology Applied

Scientific EffectSeebeck effect: Seebeck Effect

Implementation Method 2

enhancing current spreading and heat dissipation

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS9136454B2Photoelectrical element having a thermal-electrical structure

Publication Date: 2015.09.15 ENNOSTAR CORP

AI summary

A photoelectrical element comprises: a photoelectric conversion layer; a semiconductor layer formed on the photoelectric conversion layer; a conductive structure formed on the semiconductor layer; and a thermal-electrical structure formed inside the conductive structure, wherein the conductive structure comprises a transparent conductive layer formed on the semiconductor layer and a metal pad formed on the transparent conductive layer; wherein the thermal-electrical structure is formed inside the transparent conductive layer, and/or between the transparent conductive layer and the semiconductor layer, and/or between the transparent conductive layer and the metal pad, and/or inside the transparent conductive layer corresponding to the metal pad.