Semiconductor Light-Emitting Device Refractive Index Grading

Solution Overview

Problem

Diamond-based semiconductor light-emitting devices suffer from low luminous efficiency and short lifespan due to high electrical resistance and heat generation, requiring high currents that concentrate light and generate heat, leading to device deterioration.

Innovation Solution

A semiconductor light-emitting device configuration with a high refractive index first semiconductor layer and a low refractive index light-emitting layer, along with a low refractive index second semiconductor layer, is used to enhance luminous efficiency and reduce heat generation, featuring metal electrodes connected to these layers to supply current and an insulating layer to prevent electrode short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high current is supplied to diamond light-emitting device to improve luminous efficiency, then luminous efficiency is improved, but heat generation increases and device life is shortened

Engineering Contradiction:

Improveluminous efficiencyVSAvoidheat generation

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The patent introduces an intermediary material layer between the diamond light-emitting layer and the electrode. This intermediary layer has intermediate electrical resistance between diamond and metal, serving as a mediator that reduces the overall voltage drop across the device. By adding this intermediate layer, the patent resolves the contradiction by enabling lower operating currents while maintaining luminous efficiency, thus reducing heat generation without compromising light output.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If high current is supplied to diamond light-emitting device to improve luminous efficiency, then luminous efficiency is improved, but device size is increased

Engineering Contradiction:

Improveluminous efficiencyVSAvoiddevice size

Core Design Contradiction:

ProductivityVSVolume of moving object

Solution Approach 1:

The patent introduces an intermediary material layer between the diamond light-emitting layer and the electrode. This intermediary layer has intermediate electrical resistance between diamond and metal, serving as a mediator that reduces the overall voltage drop across the device. By adding this intermediate layer, the patent resolves the contradiction by enabling lower operating currents while maintaining luminous efficiency, thus reducing heat generation without compromising light output.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Illumination intensity

If diamond is used as light-emitting material due to its wide band gap, then ultraviolet light emission is achieved, but electrical resistance is high and luminous efficiency is low

Engineering Contradiction:

Improveultraviolet light emissionVSAvoidluminous efficiency

Core Design Contradiction:

Illumination intensityVSProductivity

Solution Approach 1:

The patent introduces an intermediary material layer between the diamond light-emitting layer and the electrode. This intermediary layer has intermediate electrical resistance between diamond and metal, serving as a mediator that reduces the overall voltage drop across the device. By adding this intermediate layer, the patent resolves the contradiction by enabling lower operating currents while maintaining luminous efficiency, thus reducing heat generation without compromising light output.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the electrical resistance parameter by introducing an intermediary layer with optimized resistance characteristics. This parameter change allows the device to operate at lower currents while maintaining the ultraviolet emission capability of diamond, thereby improving overall luminous efficiency without sacrificing the desired wavelength output.

Inventive Principle:

Principle #35Parameter changes

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 achieves high luminous efficiency, reduces light confinement, and extends the device's lifespan by minimizing heat generation and optimizing light extraction, resulting in a semiconductor light-emitting device with improved performance and longevity.

Implementation Method 1

The light-emitting layer is lower in refractive index than the first semiconductor layer

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

The second semiconductor layer is lower in refractive index than the light-emitting layer

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS7642542B2Semiconductor light-emitting device and producing method for the same

Publication Date: 2010.01.05 SAMSUNG ELECTRONICS CO LTD

AI summary

A semiconductor light-emitting device includes: a first semiconductor layer; a light-emitting layer being disposed on the first semiconductor layer; a second semiconductor layer being disposed on the light-emitting layer, and metal electrodes connected to the first semiconductor layer and the second semiconductor layer. The light-emitting layer is lower in refractive index than the first semiconductor layer. The second semiconductor layer is lower in refractive index than the light-emitting layer. The metal electrodes supply a current to the light-emitting layer.