Back-Side Contact GaAs Solar Cell Design
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Solution Overview
Problem
Current manufacturing techniques have not achieved efficient all-back side solar cells using compound semiconductors, which are essential for enhanced performance and efficiency in solar energy conversion.
Innovation Solution
The development of a solar cell design with all back side electrical contacts, utilizing gallium arsenide (GaAs) as the compound semiconductor, where confinement layers surround the absorbing layers, and metal contact pads are placed on these layers rather than the absorbing layers, allowing for efficient light absorption and electrical contact without shading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical contact layers are placed on the front side of the solar cell in a grid-like pattern, then electrical current collection is enhanced, but light blockage increases reducing light reaching the absorber region
Solution Approach 1:
The patent inverts the conventional location of electrical contact layers from the front side to the back side of the solar cell. This inversion allows the front surface to be fully optimized for light absorption without any metallic grid patterns blocking incident light, while the back side contacts efficiently collect electrical current generated by the absorber layer.
2Productivity
If all metallization is moved to the back side of the solar cell, then light absorption is optimized, but manufacturing complexity increases for compound semiconductors
Solution Approach 1:
The patent transitions from planar front-side contacts to back-side contacts, utilizing the third dimension (depth/thickness) of the solar cell structure. By moving contacts to the opposite surface, the design optimizes light absorption in the optical dimension while maintaining electrical functionality through structural adaptation in the spatial dimension.
3Reliability
If the entire back side of the solar cell is covered with electrical contact layer, then electrical current collection is maximized, but packaging and interconnection becomes more difficult
Solution Approach 1:
The patent segments the back-side contact layer into discrete contact regions rather than continuous coverage. This segmentation provides dedicated electrical contact points that facilitate easier packaging and interconnection while maintaining effective current collection from the entire absorber surface through the segmented contact structure.
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 enhances the efficiency of solar radiation conversion into electrical power by minimizing light blockage and enabling easier packaging and interconnection of solar cells, while also allowing for unique configurations and small form factors.
Implementation Method 1
The photovoltaic effect, which causes a solar cell to convert light directly into electrical energy, occurs inside a semiconductor material where light knocks off electrons.
Data Source
AI summary
A III-V solar cell is described herein that includes all back side contacts. Additionally, the positive and negative electrical contacts contact compound semiconductor layers of the solar cell other than the absorbing layer of the solar cell. That is, the positive and negative electrical contacts contact passivating layers of the solar cell.