Back-Contact Cell Electrode Layout to Prevent Finger Transfer Damage
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Solution Overview
Problem
Existing back contact solar cells face challenges with high costs, low reliability, and poor photoelectric conversion performance due to issues with electrode pattern designs, including high-temperature paste limitations, poor adhesion, and recombination losses from long-distance electron-hole pair diffusion.
Innovation Solution
The electrode structure for back contact cells features a design with first and second fingers, busbars, and pad points, where the distance between pad points and edges is optimized, and bent fingers are used to improve current collection without the need for large-area insulation paste, allowing for high-temperature paste use and reducing recombination losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the busbar is disposed close to the edge of the substrate and the pad points are disposed close to the edge of the substrate, then the electrode structure can improve the reliability and reduce the costs, but the fingers may be damaged during the process of transferring the back contact cell from the substrate to the battery assembly
Solution Approach 1:
The patent introduces a connection electrode that extends from the busbar in a direction toward the pad points, creating a three-dimensional electrode structure. This spatial arrangement allows the connection electrode to bridge the gap between the edge-proximity busbar and pad points without requiring the fingers to span the entire distance, thereby reducing mechanical stress and damage risk during cell transfer while maintaining the reliability benefits of edge-proximity electrode placement.
2Productivity
If the fingers are extended to collect charges from the polarity regions, then the photoelectric conversion efficiency can be improved, but the fingers may be damaged during the process of transferring the back contact cell
Solution Approach 1:
The patent divides the electrode structure into distinct functional segments: fingers for charge collection, connection electrodes for electrical connection, and busbars for current aggregation. This segmentation allows the fingers to be optimized for photoelectric conversion while the connection electrodes and busbars handle the mechanical and electrical connection functions, reducing the mechanical stress on fingers during transfer and maintaining high photoelectric conversion efficiency.
Solution Approach 2:
The connection electrode extends in a direction from the busbar toward the pad points, creating a three-dimensional electrode structure that reduces the span distance for fingers. This spatial arrangement allows fingers to be shorter and more robust while still achieving effective charge collection, thereby improving photoelectric conversion efficiency without sacrificing mechanical durability during cell transfer.
3Ease of manufacture
If the electrode structure is simplified to reduce costs, then the manufacturing cost can be reduced, but the fingers may be damaged during the transfer process
Solution Approach 1:
The patent divides the electrode structure into distinct functional segments: fingers for charge collection, connection electrodes for electrical connection, and busbars for current aggregation. This segmentation allows each component to be optimized for its specific function, enabling cost-effective manufacturing while improving mechanical durability during cell transfer.
Solution Approach 2:
The connection electrode extends in a direction from the busbar toward the pad points, creating a three-dimensional electrode structure that reduces the span distance for fingers. This spatial arrangement allows for a simpler, more cost-effective electrode design while simultaneously reducing mechanical stress on fingers during transfer, thus achieving both cost reduction and improved reliability.
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 reliability, reduces costs, increases product yield, and ensures excellent photoelectric conversion efficiency by eliminating the need for extensive insulation paste and minimizing electron-hole pair diffusion distances.
Implementation Method 1
a back contact cell, configured to convert light into electricity
Data Source
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AI summary
The disclosure provides an electrode structure of a back contact cell, a back contact cell, a back contact cell module, and a back contact cell system. The electrode structure includes: first fingers, configured to collect a first polarity region; second fingers, configured to collect a second polarity region; a first busbar, disposed on a side of the back contact cell close to a first edge and connected to the first fingers; first pad points; and first connection electrodes, respectively connected to the first busbar and the first pad points. A distance between each of the first pad points and the first edge is greater than a distance between the first busbar and the first edge. The electrode structure can improve the reliability, reduce the costs, increase the product yield, and ensure excellent photoelectric conversion efficiency.