Back-Contact Solar Cell Wavy Electrodes for Better Current Collection
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Solution Overview
Problem
Conventional solar cells have weak current collection capabilities due to gaps in the edge electrodes, particularly in interdigitated back contact (IBC) cells, which hinder the improvement of photoelectric conversion efficiency.
Innovation Solution
The implementation of connection electrodes with a wavy form that are in electrical contact with adjacent fingers, increasing the contact area and reducing gaps, combined with a non-burn-through paste to ensure continuity and minimize contact resistance, thereby enhancing current collection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional finger electrodes are used in IBC cells, then the device structure is simple, but the current collection capability is weak
Solution Approach 1:
The electrode structure is divided into multiple components: fingers for current collection, connection electrodes for interconnection, and busbars for current output. This segmentation allows each component to be optimized for its specific function, with fingers collecting current from the cell surface and connection electrodes providing low-resistance pathways between fingers and busbars.
Solution Approach 2:
The connection electrodes extend in the first direction (perpendicular to finger extension) to connect adjacent fingers, adding a dimensional aspect to current collection that was previously absent. This creates a two-dimensional current collection network rather than relying solely on the linear finger structure.
2Reliability
If straight connection electrodes are used, then the manufacturing process is simple, but the contact area with fingers is insufficient
Solution Approach 1:
The connection electrodes are designed with a wavy shape featuring multiple arcs instead of straight lines. This curvature increases the contact area between connection electrodes and fingers, providing better electrical connection and reducing contact resistance while maintaining manufacturability through screen printing processes.
3Reliability
If gaps exist between edge electrodes, then the manufacturing process is easier, but the photoelectric conversion efficiency is reduced
Solution Approach 1:
The connection electrodes merge adjacent fingers electrically by providing conductive pathways between them. This merging eliminates the functional gaps between edge electrodes, ensuring continuous current collection across the cell surface and improving photoelectric conversion efficiency without complicating the manufacturing process.
Solution Approach 2:
The connection electrodes act as intermediary elements between fingers and busbars, filling the functional gaps in the electrode structure. These intermediaries provide continuous current pathways that eliminate discontinuities and improve overall current collection efficiency.
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
The wavy connection electrodes improve current collection efficiency by increasing the contact area and reducing resistance, leading to enhanced photoelectric conversion efficiency of the solar cells.
Implementation Method 1
The connection electrode extends in the first direction in a wavy form that includes a plurality of arcs
Implementation Method 2
solar cells are being used more and more widely as a new energy alternative, which convert light energy from the sun into electrical energy. The solar cells utilize the photovoltaic principle to generate carriers
Data Source
AI summary
A back contact solar cell, including: fingers including rows of first fingers and rows of second fingers; solder joints, and a connection electrode. The fingers, the solder joints, and the connection electrode are on a first surface of the cell. The first fingers and the second fingers are alternatingly arranged along a first direction and extend in a second direction. The connection electrode extends in the first direction. A respective first finger including first and second disconnected sections of the first fingers is connected to another first finger of the first fingers via at least a portion of the connection electrode. The connection electrode extends in the first direction in a wavy form that includes a plurality of arcs.