Back-Contact Solar Cell Finger Segmentation for Lower Internal Loss
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Solution Overview
Problem
The long current transmission distance and large internal loss in back contact solar cells affect the photoelectric conversion efficiency due to the arrangement of electrode busbars and fingers, leading to increased resistance and reduced efficiency.
Innovation Solution
The solar cell design includes first and second connection segments where the first segments burn through the passivation layer to connect with the doped region, while the second segments do not, allowing for direct current collection and reduced transmission distance, thereby improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If electrode busbars and fingers are arranged on the back surface to avoid blocking the front surface, then the photoelectric conversion efficiency is improved, but the current transmission distance increases and internal loss increases
Solution Approach 1:
The electrode fingers are divided into multiple segments along the current transmission direction. Each segment is independently arranged to collect current from different regions, reducing the overall transmission distance and minimizing internal losses while maintaining the back-contact configuration that preserves front surface efficiency
Solution Approach 2:
The patent transitions from a planar two-dimensional electrode arrangement to a three-dimensional multi-layer structure. Multiple electrode fingers are arranged at different heights or depths, creating vertical current collection paths that shorten transmission distance and reduce internal resistance without blocking the front light-receiving surface
2Productivity
If electrode busbars and fingers are arranged on the back surface to avoid blocking the front surface, then the photoelectric conversion efficiency is improved, but the resistance increases
Solution Approach 1:
The electrode system is segmented into multiple shorter finger sections rather than using long continuous fingers. This segmentation reduces the length of current paths, thereby lowering resistance while maintaining effective current collection across the solar cell surface
Solution Approach 2:
Multiple electrode fingers are nested or overlapped in a three-dimensional arrangement, creating parallel current transmission paths. This nested configuration reduces the effective resistance by providing multiple conduits for current flow without requiring longer transmission distances
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 reduces current transmission distance and internal loss, enhancing the photoelectric conversion efficiency of the solar cell by optimizing the collection and transmission of electrical currents.
Implementation Method 1
The first connection segments burn through the passivation layer and are electrically connected to the doped region
Implementation Method 2
a solar cell body, where the solar cell body includes a substrate, a doped region formed on the substrate
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present application discloses a solar cell and a photovoltaic module, and belongs to the field of photovoltaic technologies. The solar cell includes a first pattern region, the first pattern region includes a plurality of first fingers extending along a first direction and arranged at intervals along a second direction, each of the first fingers includes a plurality of first connection segments disposed at intervals along the first direction and second connection segments connected between two adjacent first connection segments, and the second direction intersects with the first direction. A plurality of second connection segments are arranged at intervals along the second direction, and at least one of the first connection segments is disposed between two adjacent second connection segments. The first connection segments burn through the passivation layer and are electrically connected to the doped region, and the second connection segments do not burn through the passivation layer.