Optoelectronic Semiconductor Device with Recessed Current Spreading Layer

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Solution Overview

Problem

Radiation-generating semiconductor devices face significant light absorption losses due to contact layers, even when using transparent conductive oxides, which hampers efficient charge carrier injection and radiation emission.

Innovation Solution

An optoelectronic semiconductor device with a current spreading layer featuring a patterning of recesses on the radiation exit face, where the recesses allow radiation to exit while minimizing absorption by varying the crosswise extent and reducing material coverage, ensuring efficient charge carrier injection and reduced absorption losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a contact layer is applied over a large area on the radiation exit face to maximize charge carrier injection area, then charge carrier injection is improved, but light absorption losses increase

Engineering Contradiction:

Improvecharge carrier injectionVSAvoidlight absorption losses

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The contact spreading layer is segmented through a patterning structure with multiple recesses that extend through the layer. This segmentation creates radiation-transmissive openings while maintaining conductive regions, allowing simultaneous charge carrier injection and radiation transmission without full-layer absorption losses.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the contact spreading layer are given different properties: the ribs provide electrical conduction and charge carrier injection, while the recesses provide radiation transmission. This local differentiation allows each region to optimize its specific function without compromising the other.

Inventive Principle:

Principle #3Local quality

2Loss of energy

If a transparent conductive oxide is used for the contact layer to reduce absorption, then light transmission is improved, but charge carrier injection efficiency decreases

Engineering Contradiction:

Improvelight absorption lossesVSAvoidcharge carrier injection

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The contact spreading layer is divided into conductive ribs and recesses, where the ribs maintain electrical conductivity for charge carrier injection while the recesses allow direct radiation transmission, compensating for the reduced injection area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patterned contact spreading layer creates a porous-like structure with recesses that allow radiation to pass through. This structure provides both electrical conduction pathways and radiation transmission channels, achieving dual functionality.

Inventive Principle:

Principle #31Porous materials

3Reliability

If the current spreading layer covers the entire radiation exit face to ensure uniform current distribution, then current spreading is improved, but radiation extraction efficiency decreases

Engineering Contradiction:

Improvecurrent spreadingVSAvoidradiation extraction efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The contact spreading layer is segmented into ribs and recesses, creating a balanced structure where ribs ensure current distribution while recesses enable radiation extraction. This segmentation resolves the conflict between full coverage for current spreading and openings for radiation extraction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions serve different functions: ribs provide current spreading and electrical conduction, while recesses provide radiation extraction pathways. This local functional differentiation allows simultaneous optimization of both current distribution and radiation extraction.

Inventive Principle:

Principle #3Local quality

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 device achieves reduced radiation absorption and enhanced charge carrier injection, leading to improved efficiency and luminance distribution by optimizing the current spreading layer's patterning, which allows radiation to exit without passing through the entire thickness of the current spreading layer.

Implementation Method 1

a significant proportion of the light is lost through absorption on passage through such a contact layer

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS9859463B2Optoelectronic semiconductor device

Publication Date: 2018.01.02 AMS OSRAM INT GMBH

AI summary

An optoelectronic semiconductor device has a semiconductor body including a semiconductor layer sequence with an active region that generates radiation, a semiconductor layer and a further semiconductor layer, wherein the active region is arranged between the semiconductor layer and the further semiconductor layer, a current spreading layer is arranged on a radiation exit face of the semiconductor body, the current spreading layer connects electrically conductively with a contact structure for external electrical contacting of the semiconductor layer, in a plan view of the semiconductor device the current spreading layer adjoins the semiconductor layer in a connection region, and the current spreading layer includes a patterning with a plurality of recesses through which radiation exits the semiconductor device during operation.