Buffer-Layer Microlens Structure for Stable LED Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor light-emitting diodes face challenges with low light-emitting efficiency due to the deformation of microlenses at high temperatures, which affects the optical stability and light extraction efficiency.
Innovation Solution
A light-emitting device structure is developed, featuring a buffer layer with a transparent material and a light-emitting structure with microlens structures. Each light-emitting unit corresponds to at least one microlens structure, which includes multiple sub-layers with varying refractive indices, designed to minimize total reflection and enhance light extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a microlens is used to improve light extraction efficiency, then light extraction efficiency is improved, but the microlens deforms at high temperature causing optical instability
Solution Approach 1:
The patent changes the material parameter of the microlens from organic resin to inorganic transparent material (such as AlN, GaN, or AlGaN), which fundamentally alters the thermal stability parameter while maintaining the light extraction function. This material substitution enables the microlens to withstand high temperatures without deformation, resolving the contradiction between light extraction efficiency and optical stability.
Solution Approach 2:
The patent integrates the microlens structure with the buffer layer by using the same inorganic transparent material for both, creating a composite structure that combines the optical focusing function with thermal stability. The buffer layer serves dual purposes: as a structural foundation and as the microlens material, eliminating the need for separate organic microlens materials that would deform at high temperatures.
2Device complexity
If a single-layer microlens structure is used, then the structure is simple, but total reflection occurs reducing light extraction efficiency
Solution Approach 1:
The patent divides the microlens into multiple sub-layers with different refractive indices, creating a gradient or stepped structure that segments the optical path. This segmentation reduces total internal reflection at interfaces by gradually transitioning the refractive index, thereby improving light extraction efficiency while maintaining a relatively simple overall structure that can be integrated with the buffer layer.
Solution Approach 2:
The patent applies different refractive index properties to different sub-layers of the microlens, creating local variations in optical properties. Each sub-layer is optimized with specific refractive index characteristics to minimize reflection at particular interfaces, while the overall structure remains integrated with the buffer layer, balancing local optical optimization with global structural simplicity.
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 proposed solution improves the optical stability and light extraction efficiency of the light-emitting device by reducing the likelihood of total reflection and maintaining the structural integrity of the microlens structures at high temperatures, thereby reducing production costs and enhancing performance.
Implementation Method 1
the microlens structure includes at least two sub-layers, and each the light-emitting unit corresponds to at least one microlens structure
Data Source
AI summary
Disclosed are a light-emitting device structure and a preparation method therefor. The light-emitting device structure includes a buffer layer, where a material of the buffer layer is a transparent material; and a light-emitting structure disposed on a side of the buffer layer, where the light-emitting structure includes at least one light-emitting unit; where the buffer layer includes at least one microlens structure, the microlens structure includes at least two sub-layers, and each the light-emitting unit corresponds to at least one microlens structure. In the present disclosure, the buffer layer of the transparent material is utilized to manufacture the the microlens structure. On the one hand, a problem of total reflection is alleviated and light extraction efficiency of the light-emitting device is improved. On the other hand, no additional microlens structures is required, thereby reducing production cost.