Light Emitting Element Insulation Layer Reflective Metal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Monolithic light emitting elements face challenges in achieving high light extraction efficiency due to light absorption or reflection from lateral surfaces, and potential differences between light emitting cells can cause metal material migration, such as Ag, used for electrodes.
Innovation Solution
The light emitting element design includes a substrate with semiconductor light emitting cells, light reflective electrodes, insulation layers, and light reflective metal layers that cover lateral surfaces and spaces between cells, reducing light leakage and metal migration by maintaining a distance between wiring electrodes and using non-electrically connected light reflective metal layers to minimize electric field-induced migration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If light emitting cells are disposed closely on a single substrate to form a monolithic structure, then device integration is improved, but light extraction efficiency deteriorates due to absorption or reflection from lateral surfaces
Solution Approach 1:
An insulating layer is introduced as an intermediary substance between adjacent light emitting cells. This insulating layer fills the grooves and covers lateral surfaces, preventing direct optical interaction between cells while maintaining their close physical arrangement. The intermediary layer enables high integration density without sacrificing light extraction efficiency, as it blocks parasitic absorption and reflection from lateral surfaces.
2Area of stationary object
If wiring electrodes are placed close to light emitting cells for compact design, then device area is reduced, but metal material migration increases due to potential differences between cells
Solution Approach 1:
The insulating layer serves as a protective intermediary between wiring electrodes and light emitting cells. It covers the lateral surfaces of cells and provides electrical isolation, preventing metal material migration even when wiring electrodes are positioned close to cells. This allows compact device design without compromising reliability, as the intermediary layer blocks the migration pathway caused by potential differences.
3Device complexity
If light reflective metal layers are electrically connected to wiring electrodes for simplified structure, then manufacturing complexity is reduced, but metal material migration is caused due to electric fields
Solution Approach 1:
The insulating layer acts as an electrical intermediary that isolates light reflective metal layers from wiring electrodes. By covering the metal layers and preventing direct electrical contact, it eliminates electric field-induced metal material migration. This intermediary isolation allows the use of highly reflective metal materials without migration issues, improving light extraction efficiency without requiring complex alternative structures.
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 design enhances light extraction efficiency while reducing metal material migration, improving the overall performance and reliability of the light emitting element.
Implementation Method 1
a light reflective metal layer covering the lateral surfaces of two adjacent light emitting cells and the space between the light emitting cells via the insulation layer
Implementation Method 2
an insulation layer covering the upper surfaces and the lateral surfaces of the light emitting cells, the upper surfaces of the light reflective electrodes, and a portion of the light reflective metal layer
Data Source
Figure 1A
Figure 1B~1C
Figure 2
AI summary
A light emitting element (1;1A) includes a substrate (11); a plurality of semiconductor light emitting cells (101-108); a plurality of light reflective electrodes (13); an insulation layer that continuously covers lateral surfaces of the plurality of semiconductor light emitting cells (101-108), spaces between the plurality of semiconductor light emitting cells (101-108), lateral surfaces of the plurality of light reflective electrodes (13), and a portion of an upper surface of each of the plurality of light reflective electrodes (13); a plurality of wiring electrodes (141-149) that electrically connects the plurality of semiconductor light emitting cells (101-108) in series, and covers at least a portion of the lateral surfaces of the plurality of semiconductor light emitting cells (101-108) and the spaces between the plurality of semiconductor light emitting cells (101-108) via the insulation layer; and at least one light reflective metal layer (151-153;151) each of which covers at least a portion of the lateral surfaces of two adjacent ones of the plurality of semiconductor light emitting cells (101-108) and the space between said two adjacent ones of the plurality of semiconductor light emitting cells (101-108), via the insulation layer.