Semiconductor Light-Emitting Device Multilayer Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor light-emitting devices experience reduced light extraction efficiency due to light scattering, total reflection, and absorption by phosphor particles and resin layers, leading to low luminance and color ununiformity.
Innovation Solution
A semiconductor light-emitting device with a substrate having a plane surface, featuring a multilayer structure comprising a first light transmissible layer, a phosphor layer with a high concentration of phosphor particles, and a second light transmissible layer, which reduces total reflection and absorption, enhancing light extraction efficiency and luminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a phosphor layer with phosphor particles and resin is formed on an LED chip, then color conversion is achieved, but light extraction efficiency is reduced due to scattering, total reflection, and absorption
Solution Approach 1:
The device is divided into multiple independent layers: a first light transmissible layer, a phosphor layer, and a second light transmissible layer. Each layer performs a specific function, with the phosphor layer dedicated to color conversion and the light transmissible layers dedicated to light extraction and transmission. This segmentation allows optimization of each layer for its specific purpose, improving overall light extraction efficiency while maintaining color conversion functionality.
Solution Approach 2:
The first and second light transmissible layers act as intermediary layers between the LED chip and the external environment. These layers mediate the light transmission process by reducing total reflection at interfaces and minimizing absorption losses, thereby improving light extraction efficiency without interfering with the phosphor layer's color conversion function.
2Illumination intensity
If phosphor particles are used for color conversion, then desired color output is achieved, but color ununiformity occurs on the emission observation surface
Solution Approach 1:
By separating the phosphor layer from the resin layers, the patent creates distinct functional zones. The phosphor layer is confined to a specific region where color conversion occurs, while the light transmissible layers above and below ensure uniform light distribution. This segmentation prevents the color ununiformity that would otherwise occur on the emission observation surface.
Solution Approach 2:
The phosphor layer is positioned specifically between the two light transmissible layers, creating a localized region for color conversion. The first light transmissible layer has optimized properties for light entry and distribution, while the second light transmissible layer optimizes light exit. This local quality differentiation ensures uniform color output across the emission surface.
3Loss of energy
If a multilayer structure with light transmissible layers is formed, then light extraction efficiency is improved, but device complexity increases
Solution Approach 1:
The device structure is segmented into three main layers: a first light transmissible layer, a phosphor layer, and a second light transmissible layer. Each layer is relatively simple in composition but together they achieve improved light extraction efficiency through their coordinated arrangement and optimized optical properties.
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 multilayer structure improves light extraction efficiency and luminance by minimizing total reflection and absorption, allowing for a small point light source with high output and reduced color ununiformity.
Implementation Method 1
a semiconductor light-emitting element mounted on the plane surface of the substrate and which emits light in a range from ultraviolet ray to visible light
Implementation Method 2
a phosphor layer which covers the first light transmissible layer, the phosphor layer contacting with the plane surface of the substrate and containing phosphor particles and matrix
Data Source
AI summary
A light-emitting device is provided, which includes a substrate having a plane surface, a semiconductor light-emitting element mounted on the plane surface of the substrate and which emits light in a range from ultraviolet ray to visible light, a first light transmissible layer formed above the substrate and covering the semiconductor light-emitting element, a phosphor layer formed above the first light transmissible layer and containing phosphor particles and matrix, and a second light transmissible layer formed above the phosphor layer and contacting with the plane surface of the substrate. The surface of the phosphor layer has projections reflecting shapes of the phosphor particles.