Semiconductor Light Source With Lateral Quantum Well Conversion
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Solution Overview
Problem
Existing semiconductor light sources with directional emission characteristics, such as vertically emitting lasers and those with nanostructures and phosphor conversion layers, suffer from low efficiency and complexity in electrical contacting and light coupling, requiring complex optical systems to achieve efficient light emission.
Innovation Solution
A semiconductor light source comprising a semiconductor laser and a conversion element with three-dimensionally shaped quantum well layers that absorb primary radiation and convert it into secondary radiation, allowing for adjustable emission wavelengths and high conversion efficiency, with the quantum well layers oriented obliquely or perpendicular to the growth direction for directional emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If vertically emitting semiconductor lasers are used to achieve directional emission, then emission directionality is improved, but conversion efficiency deteriorates
Solution Approach 1:
The patent transitions from vertical emission geometry to lateral emission geometry. The semiconductor laser emits laterally into the conversion element, and the quantum well layers are oriented laterally to emit secondary radiation in the lateral direction. This dimensional change enables both directional emission and high conversion efficiency by aligning the optical paths laterally rather than vertically.
Solution Approach 2:
The patent introduces a conversion element with quantum well layers as an intermediary between the semiconductor laser and the final radiation output. The quantum well layers absorb primary radiation from the laser and convert it to secondary radiation with desired spectral properties, maintaining high conversion efficiency while achieving directional emission through lateral geometry.
2Ease of operation
If nanostructures with phosphor conversion layers are used, then directional emission is improved, but device complexity deteriorates
Solution Approach 1:
The patent merges the laser source and conversion element into a single integrated structure. The semiconductor laser and conversion element with quantum well layers are laterally coupled, eliminating the need for separate optical coupling components and complex electrical contacting schemes required by vertically emitting structures with phosphor layers.
Solution Approach 2:
The patent extracts the conversion function into a separate conversion element with quantum well layers that is laterally coupled to the laser. This extraction simplifies the overall device structure by removing the need for complex vertical stacking and multiple electrical contacts required in vertically emitting designs with phosphor conversion layers.
3Adaptability or versatility
If conventional phosphor conversion layers are used, then color adjustment is possible, but conversion efficiency deteriorates
Solution Approach 1:
The patent uses quantum well layers with adjustable bandgap energies to convert primary radiation to secondary radiation at different wavelengths. By changing the composition and thickness of the quantum well layers, the emission wavelength can be precisely controlled while maintaining high conversion efficiency through direct photoluminescence conversion rather than phosphor down-conversion.
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 semiconductor light source achieves efficient, scalable, and directional emission of colored light with high conversion efficiency, overcoming the limitations of existing technologies by using photoluminescent quantum well layers in the conversion element to set desired spectral properties and simplify electrical contacting.
Implementation Method 1
The quantum well layers are excited to photoluminescence by the primary radiation and thus optically pumped
Implementation Method 2
one or more semiconductor lasers for generating a primary radiation
Data Source
AI summary
A semiconductor light source is disclosed. In one embodiment, a semiconductor light source includes at least one semiconductor laser for generating a primary radiation and at least one conversion element for generating a longer-wave visible secondary radiation from the primary radiation, wherein the conversion element for generating the secondary radiation comprises a semiconductor layer sequence having one or more quantum well layers, and wherein, in operation, the primary radiation is irradiated into the semiconductor layer sequence perpendicular to a growth direction thereof, with a tolerance of at most 15°.