Nanostructure Semiconductor Light-Emitting Device White Light Generation
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Solution Overview
Problem
Current semiconductor light-emitting devices using nanostructures face challenges in achieving efficient light emission across a wide spectral range, particularly in producing white light, due to limitations in crystallinity and polarization effects, which affect performance and light extraction efficiency.
Innovation Solution
A nanostructure semiconductor light-emitting device is designed with multiple light-emitting nanostructures of varying diameters, heights, and pitches, each with a quantum well structure, to emit light of different wavelengths, which are combined to produce white light. The device includes a base layer, insulating layer, and light-emitting nanostructures with specific quantum well thicknesses and compositions to achieve desired emission wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If semiconductor light-emitting devices use conventional structures, then manufacturing is simpler, but crystallinity is poor and polarization effects degrade performance
Solution Approach 1:
The device divides the light-emitting region into multiple independent nanostructures (nanopillars, nanowires, or quantum dots) arranged in an array. Each nanostructure contains segmented active layers with quantum wells, allowing independent optimization of crystallinity in each unit while collectively achieving high-performance light emission across different wavelengths.
Solution Approach 2:
The invention transitions from planar two-dimensional light-emitting layers to three-dimensional nanostructures with controlled dimensions (diameter, height, pitch). This dimensional change enables exploitation of quantum confinement effects and surface effects to improve crystallinity and control emission wavelengths through geometric parameters rather than solely through material composition.
2Adaptability or versatility
If multiple nanostructures with different wavelengths are added to produce white light, then spectral range is improved, but device complexity increases
Solution Approach 1:
Different regions of the nanostructure array are assigned different local properties - specifically, nanostructures at different positions have different active layer thicknesses, compositions, or dimensional parameters. This allows each local region to emit at a specific wavelength optimized for its function, while the collective array produces the desired broad spectrum or white light.
Solution Approach 2:
The invention systematically varies key parameters (active layer thickness, quantum well composition, nanocore diameter, nanostructure pitch) across the array to tune emission wavelengths. By changing these parameters in a controlled manner, the device achieves broad spectral coverage without requiring fundamentally different structures for each wavelength band.
3Illumination intensity
If quantum well thickness is increased to improve light emission, then emission intensity is improved, but wavelength control precision decreases
Solution Approach 1:
The device employs multiple quantum wells within each active layer, where the total emission intensity is enhanced by the cumulative effect of multiple wells rather than relying on a single thick well. This dynamic arrangement allows the system to achieve high intensity while maintaining precise wavelength control through individual well thickness optimization.
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 device effectively combines light of different wavelengths to produce white light, enhancing light extraction efficiency and overcoming crystallinity and polarization issues, thereby improving the overall performance of the semiconductor light-emitting device.
Implementation Method 1
an active layer, and a second conductivity-type semiconductor layer sequentially disposed on a surface of the nanocore
Implementation Method 2
The active layer of each light-emitting nanostructure in each group has a quantum well structure, the quantum well thickness Ti of the active layers of each group satisfy the following formulas (1) and (2)
Data Source
AI summary
There is provided a nanostructure semiconductor light-emitting device including a base layer formed of a first conductivity-type semiconductor, an insulating layer disposed on the base layer and having a plurality of openings, and a plurality of light-emitting nanostructures disposed the plurality of openings, respectively. Each of light-emitting nanostructures includes a nanocore formed of a first conductivity-type semiconductor, and an active layer and a second conductivity-type semiconductor layer sequentially disposed on a surface of the nanocore. The plurality of light-emitting nanostructures are formed through the same growth process and divided into n groups (where n is an integer of two or more), each of which having at least two light-emitting nanostructures. At least one of a diameter, a height, and a pitch of the nanocores is different by group so that the active layers emit light having different wavelengths by group.