Solar Cell Electrode Layout with Edge Collection for Lower Loss
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Solution Overview
Problem
Existing solar cells and photovoltaic modules suffer from high electrical and optical losses, leading to reduced photoelectric conversion efficiency and yield.
Innovation Solution
A solar cell design with alternating rows of finger electrodes and main busbars, incorporating edge electrodes that penetrate the passivation layer to connect with the substrate, ensuring all electrodes of the same polarity are in a conduction state, thereby improving electrical connectivity and reducing losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional finger electrode patterns are used, then manufacturing is simpler, but electrical loss increases and collection efficiency decreases
Solution Approach 1:
The electrode system is segmented into multiple functional components: finger electrodes for current collection, main busbars for current transmission, and edge electrodes for edge region current collection. This segmentation allows each component to be optimized for its specific function, reducing overall electrical loss while maintaining manufacturability through standardized fabrication processes.
Solution Approach 2:
Different electrode regions are designed with different properties: finger electrodes with narrow width for minimal optical shielding, main busbars with wider width for low resistance current collection, and edge electrodes positioned at specific locations to capture edge-generated carriers. Each region's electrode characteristics are locally optimized to reduce electrical loss without requiring complete redesign of the entire electrode system.
2Productivity
If more finger electrodes are added to improve current collection, then collection efficiency increases, but optical loss increases due to shielding
Solution Approach 1:
Instead of adding excessive finger electrodes that would cause significant optical shielding, the invention uses partial action by strategically placing a limited number of edge electrodes at specific locations where they can effectively collect edge-generated carriers without substantially blocking incident light. This provides sufficient current collection improvement while minimizing optical loss.
Solution Approach 2:
The invention transitions from a two-dimensional finger electrode pattern to a three-dimensional electrode architecture by adding edge electrodes that extend along the cell edges. This dimensional addition provides new current collection pathways along the cell periphery, improving collection efficiency without requiring increased density of traditional finger electrodes that would cause optical shielding.
3Productivity
If edge electrodes are added to collect edge current, then collection efficiency improves, but device complexity increases
Solution Approach 1:
The edge electrodes are merged with the existing finger electrode fabrication process, using the same screen printing or metallization techniques. The edge electrodes are positioned to connect with the main busbars, combining multiple functions (edge current collection and main current transmission) into an integrated electrode system that doesn't require separate manufacturing steps, thus limiting the increase in manufacturing complexity.
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
Enhances the collection efficiency of solar cells by 1% to 5% and reduces defective rates, improving the overall photoelectric conversion efficiency and yield of photovoltaic modules.
Implementation Method 1
a passivation layer formed over the substrate; the finger electrodes penetrate the passivation layer to be electrically connected with the substrate
Implementation Method 2
There are two main factors affecting photoelectric conversion efficiency and yield of solar cells
Data Source
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AI summary
A solar cell and a photovoltaic module are provided. The solar cell includes a substrate and a passivation layer formed over the substrate; finger electrodes arranged in the first direction and each extending in a second direction, where the finger electrodes include rows of first finger electrodes and rows of second finger electrodes alternatingly arranged in the first direction, and each row of first finger electrodes is between two adjacent rows of second finger electrodes, and where the finger electrodes penetrate the passivation layer to be electrically connected with the substrate; main busbars arranged in the second direction and formed over the passivation layer; and at least one edge electrode extending in the second direction.