Monocrystalline silicon wafer with grooves in surface, heterojunction solar cell and preparation method

Abstract

The invention provides a monocrystalline silicon wafer with grooves in the surface, a heterojunction solar cell and a preparation method. Grooves are formed in the front face and the back face of the silicon wafer, the depth of each groove ranges from 5 micrometers to 50 micrometers, the width of each groove ranges from 10 micrometers to 100 micrometers, the internal morphology of each groove comprises one or two of a step shape and a pyramid shape, the surface morphology of the monocrystalline silicon wafer outside the grooves comprises a pyramid shape, and the surfaces of the steps and the pyramid correspond to the crystal face (111) of the silicon crystal. The distance between adjacent step edges on the same inclined plane is 0.1-10 [mu]m, and the height of the pyramid is 0.1-10 [mu]m. When the method is used for preparing the heterojunction solar cell, the contact area of the grid line and the transparent conductive film can be increased, the filling factor FF of the solar cell and the welding tension of the electrode can be improved, the shading area of the grid line can be reduced, and the short-circuit current Isc can be obviously improved; meanwhile, consumption of silver paste can be reduced, and efficiency improvement and cost reduction of the solar cell are achieved. In addition, the conductive performance of the silver paste and the speed of silk-screen printing are improved, so that the productivity of equipment is improved.

Description

Technical field [0001] The present invention relates to a silicon wafer and the texturing art heterojunction solar cells, particularly relates to a surface-single-crystal silicon substrate having a recess, and a preparation method of heterojunction solar cells. Background technique [0002] Heterojunction solar cells the conversion efficiency of the solar cell is generally higher than PERC, it has a simple structure, high open-circuit voltage, temperature characteristics, power generation, etc. can be two-sided. Heterojunction cell made using a low temperature process, the maximum temperature is generally no more than 250 deg.] C, higher temperatures can cause the amorphous silicon thin film silicon hydrogen bonds, the passivation performance deteriorates, reducing the conversion efficiency of the battery, so heterojunction cell preparing an electrode using a low temperature process is also required, usually by way of screen printing, the conductive silver paste printed on the fr...

AI Technical Summary

Problems solved by technology

[0005] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a single crystal silicon wafer with grooves on the surface, a heterojunction solar cell and a preparation method, which are used to solve the problem of heterojunction solar cells in the prior art. There are many deficiencies in the preparation of electrodes using low-temperature silver paste, including high light shading caused by the low aspect ratio of the grid lines, large series resistance caused by poor contact between the grid lines and the TCO film, and the adhesion between the grid lines and the TCO film. Low welding tension caused by weakness, high battery cost caused by large consumption of silver paste, etc.

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