Nitride LED Barrier Structure with Graded Si Doping for Low Vf
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Solution Overview
Problem
Nitride semiconductor light-emitting elements face a trade-off between reducing forward voltage Vf and maintaining high light-emission efficiency, as doping n-type impurity into the barrier layer can lower emission efficiency.
Innovation Solution
A method of growing a nitride semiconductor light-emitting element with a first barrier layer comprising a Si-doped InGaN layer and an undoped GaN layer, where the Si doping concentration is higher in the central portion of the InGaN layer than at the n-side and well layer sides, and the impurity source gas supply is adjusted across different growth stages to optimize n-type impurity distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If n-type impurity is doped into the barrier layer, then forward voltage Vf is reduced, but light-emission efficiency decreases
Solution Approach 1:
The barrier layer is divided into multiple regions with different n-type impurity concentrations: a first region adjacent to the n-type layer with higher doping concentration to reduce forward voltage, and a second region adjacent to the quantum well with lower doping concentration to maintain light-emission efficiency. This spatial variation in doping quality resolves the contradiction by optimizing each region's function locally.
Solution Approach 2:
The barrier layer is segmented into multiple distinct regions with graded doping concentrations rather than uniform doping. This segmentation allows the structure to simultaneously achieve low forward voltage (through higher doping in the first region) and high light-emission efficiency (through lower doping in the second region), resolving the technical contradiction.
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 reduces forward voltage Vf while minimizing the decrease in light-emission efficiency, resulting in a nitride semiconductor light-emitting element with improved performance in both aspects.
Implementation Method 1
doping an n-type impurity into a barrier layer of an active layer, especially into a barrier layer of an n-type layer side, allows for reducing a forward voltage Vf
Implementation Method 2
nitride semiconductor light-emitting element including a quantum well active layer
Data Source
AI summary
A nitride semiconductor light-emitting element includes: an n-side nitride semiconductor layer; a p-side nitride semiconductor layer; and an active layer between the n-side nitride semiconductor layer and the p-side nitride semiconductor layer. The active layer includes: one or more well layers comprising a first well layer that is nearest to the n-side nitride semiconductor layer, and one or more barrier layers comprising a first barrier layer between the first well layer and the n-side nitride semiconductor layer. The first barrier layer comprises a Si-doped InGaN barrier layer and an undoped GaN barrier layer in this order from the n-side nitride semiconductor layer side.