Dual Emitter Wavelength Conversion Reducing Reabsorption Losses

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Solution Overview

Problem

Optoelectronic apparatuses, such as LEDs and solar cells, face efficiency losses due to reabsorption of secondary radiation by wavelength conversion materials, which reduces the efficacy of wavelength conversion processes.

Innovation Solution

Employing dual emitters with specific electronic states that rapidly transition between excited states, minimizing reabsorption by ensuring the second base state is scarcely occupied, thus allowing for efficient conversion of primary radiation into secondary radiation with reduced reabsorption losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional wavelength conversion materials are used, then wavelength conversion can be achieved, but reabsorption of secondary radiation reduces efficiency

Engineering Contradiction:

Improvereabsorption lossVSAvoidwavelength conversion efficiency

Core Design Contradiction:

Loss of energyVSProductivity

Solution Approach 1:

The invention segments the electronic states of the wavelength conversion material into two distinct base states (first base state and second base state) with different energy levels. This segmentation allows the material to emit secondary radiation from the first excited state to the first base state, while the second base state remains unoccupied, thereby preventing reabsorption of the emitted radiation and eliminating the efficiency loss.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention changes the energy level parameters of the wavelength conversion material by introducing a dual-emitter system with specific energy level configurations. The first base state and second base state are positioned at different energy levels, with the second base state being higher in energy but unoccupied. This parameter change enables the material to convert primary radiation efficiently while preventing reabsorption, as the emitted secondary radiation cannot be reabsorbed when the higher energy second base state is unoccupied.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If wavelength conversion materials are used to convert primary radiation into secondary radiation, then radiation conversion is achieved, but the color appearance in off state may not be neutral or transparent

Engineering Contradiction:

Improveneutral color appearance in off stateVSAvoidsecondary radiation output

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The invention segments the electronic states into two base states with different characteristics. The first base state is occupied and enables efficient wavelength conversion, while the second base state remains unoccupied and does not absorb visible light, giving the material a neutral or transparent appearance in the off state. This segmentation allows the material to simultaneously achieve desired optical appearance and high conversion efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention applies local quality by assigning different functional roles to different electronic states. The first base state is optimized for wavelength conversion functionality, while the second base state is optimized for providing neutral optical appearance. This differentiation of local qualities within the material's electronic structure allows simultaneous achievement of both neutral appearance and high productivity.

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

This approach enhances the efficiency of wavelength conversion, allowing for higher secondary radiation output and potential material savings, while maintaining a neutral or transparent color appearance in the off state, particularly beneficial for display applications.

Implementation Method 1

The wavelength conversion region converts primary radiation at least in part into secondary radiation

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

The dual emitter comprises a first and a second electronic base state, together with a first electronically excited state and a second electronically excited state

Methodology Applied

Scientific EffectElectronic transition:

Implementation Method 3

reabsorption of radiation, for example, of secondary radiation which has already been formed by conversion, can distinctly reduce the efficiency of wavelength conversion

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentUS9954147B2Optoelectronic device, use of a dual emitter as wavelength conversion material

Publication Date: 2018.04.24 AMS OSRAM INT GMBH

AI summary

An optoelectronic apparatus is disclosed. In an embodiment, the apparatus includes at least one wavelength conversion region which includes at least one dual emitter as wavelength conversion material, wherein the wavelength conversion region converts primary radiation at least in part into secondary radiation, and wherein the dual emitter includes a first electronic base state and a second electronic base state, together with a first electronically excited state and a second electronically excited state which may be reached from the first electronically excited state. The dual emitter further includes emission proceeding from the second electronically excited state into the second base state.