Back Contact Solar Cell Electrode Segmentation for Carrier Path Reduction
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Solution Overview
Problem
Conventional solar cells face efficiency limitations due to long carrier moving distances and light loss caused by the design of electrodes and interconnectors, particularly at inclined parts of the semiconductor substrate, which hinder the improvement of solar cell efficiency and output.
Innovation Solution
A solar cell design featuring a back contact electrode structure with connection parts that reduce carrier moving distances by connecting outer finger parts adjacent to inclined parts, including first and second electrodes with inner and outer finger parts, and a wiring member configuration that alternately positions wiring members in the inclined parts to minimize carrier paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a back contact electrode structure with electrodes of different polarities positioned together on the back surface is used, then the electrical connection is simplified, but the carrier moving distance remains long particularly at inclined parts
Solution Approach 1:
The electrode structure is segmented into inner finger parts and outer finger parts, with the outer finger parts specifically positioned adjacent to inclined parts. This segmentation allows different regions of the electrode to serve different functions: inner finger parts for general current collection and outer finger parts for reducing carrier moving distance at critical inclined regions.
Solution Approach 2:
The patent applies local quality by providing connection parts specifically at regions adjacent to inclined parts where carriers have long moving distances. The connection parts are selectively positioned only where needed (at inclined parts) rather than uniformly across the entire electrode structure, optimizing carrier collection where it is most critical.
2Device complexity
If conventional interconnectors with a small number of ribbons are used, then the device complexity is reduced, but the carrier moving distance increases and light loss is generated
Solution Approach 1:
The patent transitions from a conventional single-surface electrode arrangement to a back-contact configuration with electrodes positioned on the back surface of the semiconductor substrate. This dimensional change allows carriers to be collected more directly at the back surface, reducing the moving distance through the bulk material and minimizing light loss that occurs when carriers traverse long paths near front surface electrodes.
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 effectively reduces series resistance and improves solar cell efficiency by shortening carrier paths and reducing output loss, enhancing the overall performance of the solar cell panel without requiring additional processing steps.
Implementation Method 1
Solar cells can be manufactured by forming various layers and electrodes according to design. However, solar cell efficiency can be determined according to the design of these various layers and electrodes.
Data Source
AI summary
Discussed is a solar cell including a semiconductor substrate having an inclined part; first and second conductivity type regions formed at or on one surface of the semiconductor substrate; a first electrode connected to the first conductivity type region on the one surface of the semiconductor substrate; and a second electrode connected to the second conductivity type region on the one surface of the semiconductor substrate. At least one of the first and second electrodes includes a finger part including a plurality of inner finger parts extending in a first direction, and a plurality of outer finger parts extending in the first direction adjacent to an edge of the semiconductor substrate; and a connection part connecting at least some of the plurality of outer finger parts on one side of the semiconductor substrate adjacent to the inclined part.