Back-Contact Solar Cell Busbar Layout for Current Mismatch Control
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Solution Overview
Problem
Current back-contact solar cells experience current mismatch between different busbars in the positive and negative electrodes, which hampers their electrical performance.
Innovation Solution
The design includes a back-contact solar cell structure where fingers and busbars are arranged alternately, with continuous fingers connecting busbar sections and connection electrodes positioned to ensure uniform current distribution, eliminating the need for insulating material between busbars and fingers of opposite polarity, thereby reducing manufacturing costs and improving photoelectric conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulating material is arranged between busbars and fingers of opposite polarity to prevent short circuits, then reliability is improved, but manufacturing cost increases and device complexity increases
Solution Approach 1:
The patent extracts and eliminates the insulating material from the structure by redesigning the busbar configuration. Busbars are divided into multiple sections with gaps between them, removing the need for insulating materials while maintaining short circuit prevention functionality.
Solution Approach 2:
Each busbar is segmented into multiple busbar sections distributed at intervals along the second direction. These sections are separated by gaps that prevent contact with fingers of opposite polarity, achieving insulation functionality through structural segmentation rather than additional insulating materials.
2Reliability
If current mismatch between different busbars is not addressed, then device complexity remains low, but electrical performance deteriorates
Solution Approach 1:
Busbars are segmented into multiple sections that are distributed at intervals, with each section connected to corresponding fingers of the same polarity. This segmentation enables better current distribution and reduces current mismatch between different busbars.
Solution Approach 2:
The patent introduces a second direction (perpendicular to the first direction of finger extension) for distributing busbar sections. This dimensional change allows busbar sections to be spaced out along the second direction, improving current convergence and reducing mismatch without increasing complexity in the primary direction.
3Reliability
If busbar sections are distributed at intervals along the second direction, then current convergence is improved, but manufacturing precision requirements increase
Solution Approach 1:
Busbar sections are distributed along the second direction (perpendicular to finger extension), creating a grid-like pattern. This dimensional arrangement improves current convergence by bringing busbar sections closer to corresponding fingers while maintaining adequate spacing, and the regular interval distribution simplifies manufacturing positioning requirements.
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 configuration effectively suppresses current mismatch, enhances carrier convergence, and improves the electrical performance and stability of the back-contact solar cell by ensuring consistent current flow and reducing the risk of short circuits.
Implementation Method 1
a back-contact solar cell, which is a solar cell in which emitters and metal contacts are arranged on its back surface and no metal electrode is arranged on its front surface. Compared with a solar cell with a metal contact arranged on its front surface, the back-contact solar cell has a higher short-circuit current and photoelectric conversion efficiency
Data Source
AI summary
This application discloses a back-contact solar cell, a solar cell structure, and a photovoltaic module. In one aspect, a back-contact solar cell includes a solar cell body, a positive electrode and a negative electrode formed on a back surface of the solar cell body. The positive electrode and the negative electrode each include a plurality of fingers, a plurality of busbars, and a connection electrode. At least one finger of the positive electrode and at least one finger of the negative electrode are continuous. Each busbar includes busbar sections distributed at intervals along a second direction. Each busbar section is separated from fingers having a polarity opposite to that of the busbar section by gaps between the busbar sections. Each connection electrode is connected to fingers having the same polarity as that of the connection electrode and insulated from fingers having a polarity opposite to that of the connection electrode.