Semiconductor Light Emitting Device Current Distribution
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Solution Overview
Problem
Current semiconductor light emitting devices face issues with current concentration at the edge areas of conductivity-type semiconductor layers, leading to reduced light emitting efficiency and reliability.
Innovation Solution
A semiconductor light emitting device is designed with a semiconductor layer of lower carrier concentration at the outer peripheral portion of the first conductivity-type semiconductor layer, which does not overlap with the first electrode, and includes a channel layer between the second conductivity-type semiconductor layer and the second electrode layer to distribute current more evenly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If current-confinement layers are used in nitride semiconductor light emitting devices, then light extraction efficiency can be improved, but current concentration occurs at the edge areas of the semiconductor layer
Solution Approach 1:
The patent applies local quality by creating a current-blocking layer with spatially varying properties. The layer has different carrier concentrations at different locations: higher concentration at the center and lower concentration at the edges. This non-uniform doping profile selectively blocks current at edge areas while maintaining current flow at the center, thereby preventing current concentration at edges and improving current distribution uniformity without compromising light extraction efficiency
2Ease of manufacture
If the semiconductor layer structure is simplified, then manufacturing complexity is reduced, but current concentration at edge areas increases
Solution Approach 1:
The patent employs parameter changes by modifying the carrier concentration parameter within the current-blocking layer. Specifically, the layer transitions from a uniform structure to one with graded carrier concentration, having higher doping at the center and lower doping at the edges. This parameter variation enables the layer to perform dual functions: blocking current at edges while allowing current flow at the center, thereby improving current distribution without adding significant structural complexity
Data Source
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AI summary
The embodiment discloses a semiconductor light emitting device (100). The semiconductor light emitting device includes a first conductive semiconductor layer (111); a first electrode layer (119) below the first conductive semiconductor layer; a semiconductor layer (120) at an outer peripheral portion of the first conductive semiconductor layer; an active layer (113) on the first conductive semiconductor layer; a second conductive semiconductor layer (115) on the active layer; and a second electrode layer (140) on the second conductive semiconductor layer.