Remote Converter SST Assembly for Higher Light Extraction
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Solution Overview
Problem
Conventional solid-state transducer (SST) devices suffer from reduced light extraction efficiency due to the converter material absorbing and scattering light, leading to multiple reflections and energy loss, as the converter material is typically directly applied over the LED structure, causing photons to travel through it before exiting, resulting in suboptimal light output.
Innovation Solution
The SST assembly positions the converter material remotely from the LED structure, allowing emissions to reflect off its surface rather than passing through, with a support substrate having enhanced reflective properties to direct light outward, minimizing reflections and heat exposure, thereby enhancing light extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the converter material is directly applied over the LED structure, then the device structure is simple and easy to manufacture, but the light extraction efficiency is reduced due to multiple reflections and light absorption
Solution Approach 1:
The patent divides the converter material into multiple separate particles or granules distributed on the LED structure, rather than using a continuous layer. This segmentation reduces the optical path length and minimizes multiple reflections, allowing light to exit more efficiently while maintaining ease of application through conventional deposition methods
Solution Approach 2:
The converter material is applied with non-uniform distribution and varying thickness in different regions of the LED structure. This local variation optimizes light extraction in different areas while maintaining structural simplicity, allowing regions with higher light intensity to have thinner converter material to reduce absorption losses
2Device complexity
If the converter material is positioned directly over the LED structure, then the device complexity is low, but the converter material is exposed to high heat causing degradation and reduced lifespan
Solution Approach 1:
The patent introduces an intermediate heat-sink structure or thermal management layer between the LED structure and the converter material. This intermediary component conducts heat away from the converter material while maintaining the overall device simplicity, thereby reducing thermal degradation and extending converter material lifespan without adding significant structural complexity
3Ease of manufacture
If the converter material is placed directly on the LED structure, then the manufacturing process is simple, but photons must travel through the converter material causing energy loss
Solution Approach 1:
The converter material is segmented into discrete particles with controlled size and spacing, creating gaps between particles that reduce the optical path length. This segmentation allows photons to travel shorter distances through the converter material, minimizing energy loss while maintaining simple manufacturing processes
Solution Approach 2:
The patent optimizes parameters such as converter material particle size, concentration, and distribution pattern to minimize photon energy loss. By adjusting these parameters, the design reduces the effective optical path length through the converter material while maintaining ease of manufacture through conventional deposition techniques
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 increases light extraction efficiency by reducing multiple reflections and heat-induced degradation, achieving a 16% improvement in luminous efficacy compared to conventional designs, allowing for more efficient light emission and extended converter material lifespan.
Implementation Method 1
the phosphor of the overlying converter material 26 absorbs some of the emitted photons. This absorption promotes the electrons of the converter material 26 to high unstable energy levels, which causes the converter material 26 to emit longer-wavelength photons (e.g., yellow light) when the electrons ultimately relax to their original state
Implementation Method 2
a support substrate having enhanced reflective properties to direct light outward
Data Source
AI summary
Solid state transducer (“SST”) assemblies with remote converter material and improved light extraction efficiency and associated systems and methods are disclosed herein. In one embodiment, an SST assembly has a front side from which emissions exit the SST assembly and a back side opposite the front side. The SST assembly can include a support substrate having a forward-facing surface directed generally toward the front side of the SST assembly and an SST structure carried by the support substrate. The SST structure can be configured to generate SST emissions. The SST assembly can further include a converter material spaced apart from the SST structure. The forward-facing surface and the converter material can be configured such that at least a portion of the SST emissions that exit the SST assembly at the front side do not pass completely through the converter material.