LED Active Layer Segmented Well and Barrier Structure
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Solution Overview
Problem
Current light emitting diodes (LEDs) face challenges in achieving efficient recombination of holes and electrons due to limitations in the structure of their active layers, which affects the intensity and color purity of emitted light.
Innovation Solution
A light emitting device with an active layer structure comprising multiple well and barrier layers, where the first well layer nearest to the second conductive type semiconductor layer has a thinner thickness and a wider band gap than the second well layer, and a barrier layer is adjusted in thickness to enhance hole injection and recombination efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the well layer thickness is increased to improve light emission, then the recombination efficiency improves, but the device complexity increases due to multiple layer configurations
Solution Approach 1:
The active layer is segmented into multiple quantum well layers (first well layer and second well layer) with different thicknesses and band gaps. The first well layer has a thinner thickness and wider band gap, while the second well layer has a thicker thickness and narrower band gap. This segmentation allows different regions to perform specialized functions, improving overall recombination efficiency while managing complexity through functional division.
Solution Approach 2:
Different well layers are assigned different local properties: the first well layer nearest to the second conductive type semiconductor layer has a thinner thickness and wider band gap to facilitate hole injection, while the second well layer has a thicker thickness and narrower band gap to enhance light emission. This local quality differentiation optimizes performance at each position within the active layer.
2Reliability
If the first well layer thickness is reduced to improve hole injection, then the hole injection efficiency improves, but the light emission intensity may decrease
Solution Approach 1:
The light emission function is segmented between two well layers: the first well layer with thinner thickness is optimized for hole injection, while the second well layer with thicker thickness is optimized for light emission. This segmentation allows each layer to specialize in its primary function without compromising the other.
Solution Approach 2:
The first well layer has a thinner thickness specifically at the region nearest to the second conductive type semiconductor layer to enhance hole injection efficiency, while the second well layer has a thicker thickness to maximize light emission intensity. Each location has optimized properties suited to its specific function.
3Reliability
If multiple barrier layers with different band gaps are introduced to improve recombination, then the recombination energy level improves, but the manufacturing precision requirements increase
Solution Approach 1:
The barrier layers are segmented into multiple distinct layers with different band gaps (first barrier layer, second barrier layer, and third barrier layer). Each barrier layer is positioned between specific well layers and has optimized thickness and band gap properties. This segmentation enables precise control of carrier transport and recombination energy levels through graded band gap structures.
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 improves the inner quantum efficiency, increases the recombination of holes and electrons, and enhances the intensity and color purity of the emitted light, leading to a more reliable light emitting device.
Implementation Method 1
a first well layer between the first barrier layer and the second barrier layer, the first well layer having a third band gap; and a second well layer between the second barrier layer and the at least one third barrier layer, the second well layer having a second band gap, the first well layer has a thickness thinner than that of the second well layer; and the third band gap is different from the first band gap
Implementation Method 2
a light emitting device in which a well layer which is the nearest to a second conductive type semiconductor layer has a relatively thin thickness to improve a recombination energy level
Implementation Method 3
Light emitting diodes (LEDs) are light emitting devices that convert an electric current into light
Implementation Method 4
a plurality of barrier layers comprises: a first barrier layer which is the nearest to the second conductive type semiconductor layer, the first barrier layer having a first band gap; a second barrier layer adjacent to the first barrier layer; and at least one third barrier layer between the second barrier layer and the first conductive type semiconductor layer
Data Source
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AI summary
A light emitting device is provided. The light emitting device comprises a first conductive type semiconductor layer, a second conductive type semiconductor layer on the first conductive type semiconductor layer, and an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer, the active layer comprising a plurality of well layers and a plurality of barrier layers. The plurality of barrier layers comprise a first barrier layer which is the nearest to the second conductive type semiconductor layer, the first barrier layer having a first band gap, a second barrier layer adjacent to the first barrier, and at least one third barrier layer between the second barrier layer and the first conductive type semiconductor layer. The plurality of well layers comprise a first well layer between the first barrier layer and the second barrier layer, the first well layer having a third band gap, and a second well layer between the second barrier layer and the at least one third barrier layer, the second well layer having a second band gap. The first well layer has a thickness thinner than that of the second well layer, and the third band gap is different from the first band gap.