A method for preparing the back of a perc single crystal double-sided solar cell

Abstract

The invention discloses a method for preparing the back surface of a PERC single crystal double-sided solar cell, comprising the following steps: S1, depositing a passivation layer on the back surface of a silicon substrate; S2, using a low-energy laser to irradiate the passivation layer with laser light, so that the laser irradiates the passivation layer with laser light. The lower passivation layer forms a groove, and the silicon substrate in the groove is exposed; S3, deposit a protective layer on the surface of the groove and the passivation layer, and the protective layer is a silicon nitride film; S4, use electronic paste to burn through the groove The protective layer is prepared, and the back electrode is in contact with the silicon substrate in the groove. In the method for preparing the back of the PERC single crystal double-sided solar cell, immediately after depositing the passivation layer, a low-energy laser is used for grooving, which reduces damage to the silicon substrate and reduces energy consumption, and then deposits a protective layer, which not only realizes the protection of the passivation layer It also has a repairing effect on the surface of the silicon substrate and in the body, reducing the recombination center and improving the conversion efficiency of the battery.

Description

technical field [0001] The invention relates to the technical field of backside preparation of PERC cells, in particular to a method for preparing the backside of a PERC single crystal double-sided solar cell. Background technique [0002] PERC technology is to add a passivation layer (alumina or silicon oxide) on the back of the silicon wafer to passivate the silicon wafer, which can effectively improve the minority carrier lifetime. In order to prevent the passivation layer from being damaged and affecting the passivation effect, a protective layer (silicon nitride) is also plated on the outside of the passivation layer. Since the passivation layer is an insulating layer, it cannot form an electrode path with the aluminum back field. Therefore, it is necessary to groove the back side of the silicon wafer by laser to expose the silicon substrate and form the local surface field of the PERC monocrystalline silicon solar cell. [0003] At present, the production process of t...

AI Technical Summary

Problems solved by technology

This method must use a high-energy laser to irradiate the silicon substrate to remove the laminated passivation dielectric film deposited on a specific area on the back, so the silicon substrate will inevitably be damaged during the laser ablation process, thereby causing damage to the silicon substrate surface and the silicon substrate. Defects occur in the substrate body, which affects the electrical properties of the solar cell. In addition, when high laser energy is used for ablation, the energy consumption of the laser is bound to increase, thereby increasing the manufacturing cost of the back of the solar cell.

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