Semiconductor Light-Emitting Device with Hole Electrode
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Solution Overview
Problem
In semiconductor light-emitting devices, the close proximity of electrodes leads to uneven current density and reduced luminous efficiency due to concentrated current flow, resulting in ununiform light emission intensity.
Innovation Solution
A semiconductor light-emitting device with a substrate having a semiconductor multilayer film divided into portions by grooves, featuring a hole in each light-emitting element for a columnar first electrode and an annular second electrode, allowing current to flow uniformly across the light-emitting layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the distance between adjacent light-emitting elements is reduced to increase integration density, then the manufacturing precision and area utilization improve, but the current density becomes ununiform and luminous efficiency decreases
Solution Approach 1:
The patent segments the light-emitting layer into multiple independent light-emitting elements arranged in a matrix pattern, with each element having its own electrodes. This segmentation allows for better current distribution control while maintaining high integration density, resolving the contradiction between manufacturing precision and luminous efficiency
Solution Approach 2:
The patent applies local quality by creating different electrode configurations for different regions of the light-emitting element. The first electrode is positioned at a specific location while the second electrode surrounds it, creating localized current paths that ensure uniform current density distribution across the light-emitting layer, thereby maintaining high luminous efficiency even when elements are closely spaced
2Area of stationary object
If the electrodes are placed close together to reduce device size, then the area and compactness improve, but the current concentrates in certain areas causing ununiform light emission
Solution Approach 1:
The patent employs asymmetric electrode placement where the first electrode is positioned at a specific location and the second electrode surrounds it in a non-symmetric configuration. This asymmetric design creates optimized current paths that distribute current uniformly across the light-emitting layer even when electrodes are placed close together, maintaining uniform light emission while minimizing device area
Solution Approach 2:
The patent transitions from planar electrode placement to a three-dimensional configuration where the second electrode surrounds the first electrode in a surrounding manner. This dimensional change allows for better current distribution control in multiple directions, ensuring uniform light emission intensity while keeping the device compact
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 achieves more uniform current distribution and improved luminous efficiency by reducing high current density areas, enhancing light emission uniformity and overall performance.
Implementation Method 1
a light-emitting layer and a second conductive layer of p-type formed over a SiC substrate in the stated order, is partitioned by etching into a plurality of light-emitting elements
Data Source
AI summary
A semiconductor light-emitting device having a substrate on which a semiconductor multilayer film is disposed, the semiconductor multilayer film having a layered structure in which a first conductive layer, a light-emitting layer and a second conductive layer are layered above the substrate from bottom to top in the stated order, and being divided into portions by grooves extending perpendicular to the substrate, each portion having a diode structure and serving as a light-emitting element 12, each light-emitting element 12 having a hole 22 in a central portion thereof in plan view, the hole 22 penetrating through the second conductive layer 18 and the light-emitting layer 16 and reaching the first conductive layer 14, and comprising: a first electrode 24 inserted in the hole 22 and having a columnar shape, one end thereof being connected to the first conductive layer 14 at the bottom of the hole 22, and the other end protruding from an opening of the hole 22; and a second electrode 26 formed on the second conductive layer 18 and having an annular shape surrounding the opening of the hole22.