Device and method for processing edge leakage of solar cells

Abstract

The invention discloses a solar cell edge leakage processing device and a processing method, which are used to solve the deficiencies in the prior art in processing the solar cell edge leakage and improve the conversion efficiency of the battery. The edge leakage treatment device of the solar cell includes: an etching solution tank, a bias power supply, at least one wire and a current detection device; the etching solution tank is used to hold the etching solution; the bias power supply is arranged outside the etching solution tank, and the The wires are respectively connected to the front and back electrodes of the solar cells to be processed, and are used to apply a reverse bias voltage to the solar cells placed in the etchant tank, so that the etching rate of the edge leakage area of ​​the solar cell is greater than that of the edge non-leakage area. Etching rate; the current detection device is set outside the etching solution tank and connected to the bias power supply to detect the current value between the front and back electrodes of the solar cell. When the current value is less than the preset current value, a control signal is sent Give the bias power supply, and control the bias power supply to stop working.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to an edge leakage processing device and method for solar cells. Background technique [0002] With the continuous improvement of the strategic position of energy in the national economy and the continuous development of solar energy utilization technology, photovoltaic power generation systems have received extensive attention, and low cost and high efficiency are the direction of its future development. Photovoltaic power generation systems include photovoltaic power generation components and photovoltaic system balance components (Balance of System, BOS), in which BOS accounts for an increasing proportion of the cost of photovoltaic power generation systems and it is difficult to reduce costs. Therefore, it is necessary to improve the conversion efficiency of photovoltaic power generation components It is particularly important to reduce the cost of photovoltaic power generat...

AI Technical Summary

Problems solved by technology

All of the above methods will cause new unpassivated edges, resulting in an increase in the recombination rate of carriers at the edge and a decrease in cell efficiency.

[0007] In the mask method, during the PVD process, at least one of the front and back sides of the battery needs to be provided with an edge mask at the edge. The shielding of the edge mask can prevent the conductive material from depositing on the edge of the battery, but due to the Process errors such as mask processing errors can easily cause a gap between the edge mask and the edge of the battery. Under vacuum conditions, the free diffusion of metal atoms is relatively large, and it is easy to diffuse through the gap between the crystalline silicon and the mask. Deposits to the edge of the battery, causing leakage problems

[0008] In summary, the existing methods to solve the edge leakage of silicon heterojunction solar cells have their own shortcomings: because heterojunction cells are very sensitive to edge defects, mechanical wear and edge removal methods or laser scribing methods will introduce new non-destructive defects. Passivate the edge area, thereby reducing the battery efficiency; the plasma etching method and the solution etching method can only etch the edge fixed area, and cannot solve the leakage problem existing outside the fixed area; the mask plate method Higher requirements on equipment and inaccurate alignment of mask plates, etc., lead to short circuit of front and back transparent conductive oxide thin film electrodes, reducing battery fill factor

[0009] In addition, the leakage area usually exists in a certain local area of ​​the edge, not the entire edge area of ​​the silicon wafer. The prior art process is to process the entire edge, and cannot perform selective area treatment on the edge leakage local area; the prior art method for preventing leakage Only for the leakage problem caused by the edge interconnection of the front and back electrodes of the battery, it cannot solve the composite leakage problem caused by the edge material defect

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