Vertical Cavity Light Emitter with Recessed Active Layer Relief
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Solution Overview
Problem
Vertical cavity-type semiconductor lasers have lower luminous efficiency compared to horizontal cavity-type semiconductor lasers due to distortions in the active layer caused by lattice mismatch and piezoelectric fields, which reduce the recombination probability of electrons and holes.
Innovation Solution
A vertical cavity light-emitting element with a semiconductor structure layer featuring a recessed groove that passes through the active layer, reducing distortions and enhancing the internal quantum efficiency by minimizing piezoelectric fields and current confinement, coupled with multilayer reflectors to optimize light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a vertical cavity structure is used, then the device complexity is reduced and fabrication is simplified, but the luminous efficiency decreases due to distortions in the active layer
Solution Approach 1:
The patent introduces recessed portions at specific locations in the active layer to create local variations in the structure. These recessed portions are strategically positioned to reduce distortion and piezoelectric fields in critical areas, thereby improving carrier recombination efficiency and luminous efficiency without changing the overall vertical cavity structure
Solution Approach 2:
The patent adds a depth dimension to the active layer by forming recessed portions that extend downward from the surface. This creates a three-dimensional structure within the two-dimensional plane of the active layer, allowing for localized stress relief and field reduction while maintaining the vertical cavity configuration
2Manufacturing precision
If the active layer is made uniform, then the manufacturing precision is improved, but the internal quantum efficiency decreases due to piezoelectric fields and lattice mismatch distortions
Solution Approach 1:
The patent creates non-uniform recessed portions within the uniformly manufactured active layer. This local structural variation addresses the piezoelectric field and lattice mismatch issues in specific regions without compromising the overall manufacturing precision and uniformity of the active layer
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 design improves luminous efficiency by reducing distortions in the active layer, leading to higher internal quantum efficiency and concentrated light emission, resulting in a higher output and density of laser light.
Implementation Method 1
by application of voltage to a semiconductor layer via electrodes, a light emitted from the semiconductor layer resonates in the optical resonator to generate a laser light
Implementation Method 2
a light emitted from the semiconductor layer resonates in the optical resonator to generate a laser light
Implementation Method 3
a first multilayer reflector, a semiconductor structure layer, an electrode layer, and a second multilayer reflector
Implementation Method 4
multilayer reflectors opposed to one another with the semiconductor layer interposed therebetween
Data Source
AI summary
A vertical cavity light-emitting element includes a substrate, a first multilayer reflector, a semiconductor structure layer, an electrode layer, and a second multilayer reflector. The semiconductor structure layer includes a first semiconductor layer of a first conductivity type on the first multilayer reflector, a light-emitting layer on the first semiconductor layer, and a second semiconductor layer of a second conductivity type on the light-emitting layer. The electrode layer is on an upper surface of the semiconductor structure layer and is electrically in contact with the second semiconductor layer in one region of the upper surface. The second multilayer reflector covers the one region on the electrode layer and constitutes a resonator with the first multilayer reflector. The semiconductor structure layer has one recessed structure including one or a plurality of recessed portions passing through the light-emitting from the upper surface in a region surrounding the one region.