P-type PERC double-faced solar cell employing laser marking alignment and preparation method thereof

Abstract

The invention discloses a P-type PERC double-faced solar cell employing laser marking alignment and a preparation method thereof. The P-type PERC double-faced solar cell comprises back electrodes, a back side silicon nitride film, an alumina film, P-type silicon, an N-type emitter electrode, a front side silicon nitride film and positive silver electrodes which are sequentially arranged from bottom to top. Each back electrode is formed by a back electrode main grid and a back aluminum grid line which are vertically crossed and are connected with each other, the back side silicon nitride film is provided with several grooves traversing the back side silicon nitride film and the alumina film to form laser grooving zones, the P-type silicon is exposed in the grooves, the parts, of the back aluminum grid lines, arranged in the grooves are connected with the P-type silicon, the back side silicon nitride film is provided with laser marks, relative positions of the laser marks and the laser grooving zones are preset, by positioning the laser marks and in dependence on the distance between the laser grooving zones and the laser marks, the printing back aluminum grid lines are aligned. According to the invention, aluminium paste on the back side of each silicon chip can accurately cover the laser grooving zones, and the fraction defective of the double-faced PERC solar cells can be effectively reduced.

Description

technical field [0001] The invention relates to solar cell technology, in particular to a P-type PERC double-sided solar cell that adopts laser marking alignment, and also relates to a preparation method of the solar cell. Background technique [0002] A crystalline silicon solar cell is a device that effectively absorbs solar radiation energy and converts light energy into electrical energy by using the photovoltaic effect. When sunlight shines on the semiconductor P-N junction, new hole-electron pairs will be formed. Under the action of the electric field of the P-N junction, the holes flow from the N region to the P region, and the electrons flow from the P region to the N region. After the circuit is turned on A current is formed. [0003] Traditional crystalline silicon solar cells generally only use front passivation technology, that is, a layer of silicon nitride is deposited on the front of the silicon wafer by PECVD to reduce the recombination rate of minority carr...

AI Technical Summary

Problems solved by technology

However, this silicon wafer edge alignment method has the following defects: there will be errors in the silicon wafer manufacturing process, so that its shape may not be a standard square shape, and the silicon wafer edge alignment method will cause inaccurate positioning. , this is because the printing machine determines the position of the aluminum paste to be printed according to the distance between the edge of the silicon wafer and the laser grooved area during printing, and the shape of the silicon wafer is not a regular square, which directly leads to the back of each silicon wafer The aluminum paste cannot be printed accurately on the laser grooved area, which increases the defect rate of double-sided PERC solar cells

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