Double-sided photovoltaic cell, laser cutting method and photovoltaic module

Abstract

The invention belongs to the field of photovoltaic technology and provides a double-sided photovoltaic cell, a laser cutting method and a photovoltaic assembly. The double-sided photovoltaic cell provided by the present invention includes a cell body, the back of the cell body includes at least two thin grid lines, and the back of the cell body further includes at least one metal back field, the metal back field It is arranged between two adjacent thin grid lines. In the present invention, a metal back field is added to the starting area and / or the ending area of ​​the non-destructive laser cutting track on the back side of the double-sided photovoltaic cell to form local metallization protection for the battery sheet. In the process of opening the induction groove for the laser burning of the cell, the direction of the laser burning is to reach the cell through the metal back field, which avoids the damage to the cell caused by the direct laser burning, and makes it difficult for the surface of the cell to form fine cracks. Reduces the occurrence of chipping of cutting edges or chipped cells.

Description

technical field [0001] The invention belongs to the field of photovoltaic technology, and particularly relates to a double-sided photovoltaic cell, a laser cutting method and a photovoltaic assembly. Background technique [0002] As a new battery welding process, stitch welding technology realizes the superposition of battery cells on the basis of the traditional ribbon welding process, reduces the spacing between cells, maximizes the utilization area, and achieves high energy density. During the preparation of stitch-bonded solar modules, after the silicon wafers are sorted, the silicon wafers need to be cut and pretreated, and then the silicon wafers are lapped and welded based on the welding technology using flexible welding tapes and custom tooling. Among them, the traditional silicon wafer cutting method is to use a pulsed laser with high energy density to draw a groove on the silicon wafer, and then mechanically break it apart. The section of the silicon wafer cut by ...

AI Technical Summary

Problems solved by technology

The cross-section of the silicon wafer cut by the traditional method was observed with a scanning electron microscope, and it was found that the cross-section was extremely uneven, obviously wavy, and had many burrs and cracks. Melting phenomenon, which caused severe cutting damage to the silicon wafer

Since there is stress at the intersection point between laser cutting and mechanical breaking, and the cutting part of the silicon wafer is located at the rolling position of the ribbon, the damage to the silicon wafer caused during the cutting process will eventually affect the quality of the stitch-welded solar module. After pressing, there are more texture cracks

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