Semiconductor Light Emitting Element Open Failure Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor light emitting elements are prone to open failures due to disconnections in the transparent electrode layer, which can lead to a loss of functionality in light emitting apparatuses when current concentration occurs, especially when multiple elements are connected in series.
Innovation Solution
The semiconductor light emitting element design includes a transparent electrode layer with a specific thickness and a second pad electrode that forms a Schottky contact with the second semiconductor layer, creating a current path through an overvoltage breakdown if disconnection occurs, thereby preventing open failures and maintaining light emission in connected devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the transparent electrode layer is made thin to reduce light absorption, then light extraction efficiency is improved, but the layer becomes prone to disconnection and open failures
Solution Approach 1:
The patent applies preliminary action by forming a protective structure (insulator layer with opening) before the transparent electrode layer is deposited. This pre-formed structure prevents current concentration at step portions during the electrode formation process, thereby preventing disconnection while maintaining thin electrode thickness for optimal light extraction.
Solution Approach 2:
The insulator layer with an opening acts as an intermediary structure between the p-type semiconductor layer and the transparent electrode layer. It provides a planar surface that eliminates step portions, preventing current concentration and disconnection in the thin transparent electrode layer while allowing electrical connection through the opening.
2Reliability
If the p-side pad electrode area is enlarged to reduce current concentration, then open failure resistance is improved, but light absorption by the electrode increases
Solution Approach 1:
The patent forms the insulator layer with an opening before depositing the transparent electrode layer and pad electrode. This preliminary structure prevents current concentration at step portions, allowing the pad electrode to maintain a smaller area without risking disconnection, thereby reducing light absorption while ensuring reliability.
3Power
If multiple semiconductor light emitting elements are connected in series to increase output, then light emitting power is improved, but the system becomes more vulnerable to open failures
Solution Approach 1:
The patent applies preliminary action by forming the protective insulator layer structure before connecting multiple elements in series. This pre-formed protection against current concentration and disconnection in each individual element ensures that the entire series-connected system maintains high reliability, allowing high light emitting power to be achieved without increased vulnerability to open failures.
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 design effectively secures a current path even if a disconnection happens in the transparent electrode layer, ensuring that the semiconductor light emitting device does not lose its functionality as a whole, even if one element fails, by distributing current homogeneously through the Schottky contact.
Implementation Method 1
a second pad electrode that forms a Schottky contact with the second semiconductor layer, creating a current path through an overvoltage breakdown if disconnection occurs
Implementation Method 2
creating a current path through an overvoltage breakdown if disconnection occurs
Implementation Method 3
emits a light by recombination of an electron and a hole injected into the light emitting layer from the n-type semiconductor layer and the p-type semiconductor layer, respectively
Implementation Method 4
Since the transparent electrode layer is generally formed by sputtering
Data Source
Figure 1A~1C
Figure 2A~2B
Figure 3~4
AI summary
Provided is a semiconductor light emitting element wherein generation of an open failure of the light emitting device can be eliminated by ensuring a current pathway when disconnection is generated in a transparent electrode layer. A semiconductor light emitting element (10) is provided with: a first semiconductor layer (12) on a substrate (11); a light emitting layer (13) on the first semiconductor layer (12); a second semiconductor layer (14) on the light emitting layer (13); an insulator layer (15) provided with a hole portion (19) in a partial region on the second semiconductor layer (14); a transparent electrode layer (16) covering the upper surface of the insulator layer (15) and the second semiconductor layer (14) without covering the hole portion (19); and a second pad electrode (18) brought into contact with the second semiconductor layer (14) through the hole portion (19) and faces the insulator layer (15) with the transparent electrode layer (16) therebetween. Contact resistance between the second pad electrode (18) and the second semiconductor layer (14) is set larger than that between the transparent electrode layer (16) and the second semiconductor layer (14).