Nanostructure LED Wavelength Stability via Surface Segmentation
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Solution Overview
Problem
Nanostructure semiconductor light emitting devices face issues with unstable wavelengths and leakage current due to differences in crystal planes on the upper surfaces of nanostructures, leading to reduced luminous efficiency and optical characteristics.
Innovation Solution
The device features a base layer with insulating openings exposing regions for light emitting nanostructures, where the active layer is only disposed on the side surfaces of nanocores with specific crystal planes, and the upper surfaces are free of the second conductivity-type semiconductor layer to prevent light emission and leakage current, enhancing luminous efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If active layers are grown on upper surfaces of nanostructure, then light emitting area is increased, but wavelength stability deteriorates and leakage current is generated
Solution Approach 1:
The patent segments the nanostructure surface into side surfaces and upper surfaces, placing active layers only on side surfaces while leaving upper surfaces free of active layers. This segmentation resolves the contradiction by maintaining light emission from side surfaces while preventing wavelength instability and leakage current from upper surfaces.
Solution Approach 2:
The patent applies local quality by creating different structural characteristics on different surfaces of the nanostructure. The side surfaces have active layers for light emission, while the upper surfaces are kept free of active layers and second conductivity-type semiconductor layers, giving each surface its optimal local quality for its specific function.
2Area of stationary object
If active layers are grown on upper surfaces of nanostructure, then light emitting area is increased, but leakage current is generated
Solution Approach 1:
The patent extracts the harmful element (second conductivity-type semiconductor layer) from the upper surface of the nanostructure while retaining it on the side surfaces where it serves a useful function. This extraction eliminates leakage current generation from the upper surface while preserving the light emitting area on the side surfaces.
Solution Approach 2:
The patent applies local quality by creating different structural characteristics on different surfaces of the nanostructure. The side surfaces have active layers for light emission, while the upper surfaces are kept free of active layers and second conductivity-type semiconductor layers, giving each surface its optimal local quality for its specific function.
3Area of stationary object
If different crystal planes are disposed on upper surface of nanostructure, then light emitting area is increased, but wavelength uniformity deteriorates
Solution Approach 1:
The patent segments the nanostructure surface into side surfaces and upper surfaces, placing active layers only on side surfaces while leaving upper surfaces free of active layers. This segmentation resolves the contradiction by maintaining light emission from side surfaces while preventing wavelength instability and leakage current from upper surfaces.
Solution Approach 2:
The patent applies local quality by creating different structural characteristics on different surfaces of the nanostructure. The side surfaces have active layers for light emission, while the upper surfaces are kept free of active layers and second conductivity-type semiconductor layers, giving each surface its optimal local quality for its specific function.
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 configuration stabilizes the wavelengths of emitted light, reduces leakage current, and improves luminous efficiency by maintaining required optical characteristics and preventing light emission on non-planar upper surfaces, resulting in a more precise and efficient light emission.
Implementation Method 1
A semiconductor light emitting device such as a light emitting diode (LED) is a device including materials emitting light, and may convert energy generated through the recombination of electrons and electron holes within a junction semiconductor into light to be emitted therefrom.
Data Source
AI summary
A nanostructure semiconductor light emitting device includes a base layer, an insulating layer and a plurality of light emitting nanostructures. The base layer is formed of a first conductivity type semiconductor. The insulating layer is disposed on the base layer and has a plurality of openings through which regions of the base layer are exposed. Each of the light emitting nanostructures is disposed on the exposed regions of the base layer and includes nanocore formed of a first conductivity type semiconductor, and an active layer and a second conductivity-type semiconductor layer sequentially disposed on side surfaces of the nanocore. Upper surfaces of the light emitting nanostructures are non-planar and contain portions free of the second conductivity-type semiconductor layer in order to prevent light emissions during device driving.