High-efficiency back contact solar cell back sheet without main grids, high-efficiency back contact solar cell assembly without main grids and manufacturing technology

Abstract

The invention relates to the field of solar cells, in particular to a high-efficiency back contact solar cell back sheet without main grids, a high-efficiency back contact solar cell assembly without main grids and a manufacturing technology of the high-efficiency back contact solar cell assembly. The back contact solar cell back sheet is characterized by sequentially comprising an electric connection layer and a basic layer from top to bottom, the electric connection layer and the basic layer are connected through adhesive, and the electric connection layer comprises two or more finger-shaped electrodes, all the finger-shaped electrodes are alternatively arrayed in an interdigital shape, and the electric connection layer is used for being connected with a back contact cell piece. The back contact solar cell back sheet has the advantages of being high in efficiency and resistant to subfissure, shading losses of grid line electrodes on the front face are eliminated, and therefore the cell efficiency is improved; the cell can be sheeted, and therefore the cost is lowered; practicability is higher, and the back contact solar cell back sheet is generally suitable for an MWT structure, an EWT structure, an IBC structure and other structures.

Description

technical field [0001] The invention relates to the field of solar cells, in particular to a busbar-free, high-efficiency back-contact solar cell backplane, components and a preparation process thereof. Background technique [0002] Energy is the material basis of human activities. With the continuous development and progress of human society, the demand for energy is increasing day by day. Traditional fossil energy is non-renewable energy and it is difficult to continue to meet the needs of social development. Therefore, research and utilization of new energy and renewable sources have become increasingly popular in countries around the world in recent years. Among them, solar power generation technology has the advantages of directly converting sunlight into electricity, simple use, environmental protection and pollution-free, high energy utilization rate, etc., and has received widespread attention. Solar power generation uses large-area P-N junction diodes to generate p...

AI Technical Summary

Problems solved by technology

This process has the following defects: 1. The composite conductive backplane used is a composite conductive metal foil in the backplane, usually copper foil, and the copper foil needs to be laser etched or chemically etched

Since laser etching is still operable for simple patterns, the etching speed is slow and the production efficiency is low for complex patterns, while chemical etching requires pre-prepared complex-shaped and corrosion-resistant masks, environmental pollution and corrosive liquids on polymers. Substrate corrosion problems

Therefore, the manufacturing process of the conductive backplane manufactured in this way is complicated and the cost is extremely high.

2. It is necessary to punch the packaging material of the back layer of the solar cell so that the conductive adhesive can penetrate the packaging material. Since the packaging material is usually a viscoelastic body, it is extremely difficult to accurately punch holes

3. Accurate dispensing equipment is required to coat the conductive glue on the corresponding position of the back plate. It can also be operated for batteries with fewer back contacts such as MWT, and for back contact batteries with small and large number of back contacts such as IBC. Simply not possible with dispensing equipment

However, a large number of conductive parts are required to effectively collect current, thus resulting in increased manufacturing costs and complicated process steps

[0009] Patent EP2709162A1 discloses a solar cell, which is applied to a back-contact solar cell. It discloses electrode contact units that are separated from each other and arranged alternately. The electrode contact units are connected by longitudinal connectors to form an "I"-shaped electrode structure; but this structure Two connections are made on the battery sheet. The first is the connection between the battery sheet and the electrode contact unit, and then the electrode contact unit needs to be connected through the connector. The two connections bring complexity in the process and cause too many electrodes The contact point may cause "disconnection" or "wrong connection", which is not conducive to the overall performance of the back contact solar cell

[0010] Patent WO2011143341A2 discloses a back-contact solar cell, including a substrate, a plurality of adjacent P-doped layers and N-doped layers are located on the back of the substrate, the P-doped layers and N-doped layers are stacked with a metal contact layer, and A passivation layer is provided between the P-doped layer, the N-doped layer and the metal contact layer, and there are a large number of nano-connection holes on the passivation layer, and the nano-connection holes connect the P-doped layer, the N-doped layer and the metal contact layer. Metal contact layer; however, the invention uses nanopores to connect the metal contact layer, which will increase the resistance, and the manufacturing process is complicated, which has higher requirements for manufacturing equipment

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