Method for preparing metal electrodes of crystal silicon solar cell

Abstract

The invention discloses a method for preparing metal electrodes of a crystal silicon solar cell, which comprises the steps that: after the PN junction is prepared on a p-type crystal silicon substrate through diffusion, a silicon nitride antireflection layer is prepared on the surface of a n type emitting electrode, then, a thin Al layer with the thickness being 100nm to 1000nm is prepared on thesurface of a p-type conducting back through the vacuum sputtering technology, the vapor deposition technology or the screen printing technology, in addition, a thin Ag grid line layer with the thickness being 1mum to 5mum is prepared on the surface of the silicon nitride antireflection layer through the screen printing, next, an Al back field seed layer and an Ag grid line seed layer are formed through the traditional high-temperature sintering technology, finally, tin, copper or nickel is electroplated on the Ag grid line seed layer and the Al back field seed layer through the electroplatingprocess, and the metal electrodes are formed after the thickening. Compared with the prior art, the method combines the advantages of the screen printing process, the magnetron sputtering process, the vapor deposition process and the electroplating process, front metal grid line electrodes with high electrical conductivity and low light shielding rate can be obtained, and simultaneously, the consumption of expensive metal Ag can be effectively reduced, so important industrialized application prospects are realized.

Description

technical field [0001] The invention relates to the technical field of crystalline silicon solar cells, in particular to a method for preparing a metal electrode of a crystalline silicon solar cell. Background technique [0002] In solar cell applications, crystalline silicon solar cell technology is relatively mature, and its cumulative market share accounts for about 85%. However, at the current stage, the amount of silicon material used in the manufacture of crystalline silicon solar cells is too large, so the overall energy consumption is relatively high, which greatly limits the cost reduction of crystalline silicon solar cells. [0003] In order to reduce the production cost per watt of crystalline silicon solar cells and improve their photoelectric conversion efficiency, crystalline silicon solar cells with ultra-thin silicon substrates, high emitter square resistance, and low surface doping concentration are the focus of current research and development. However, th...

AI Technical Summary

Problems solved by technology

However, there are two problems in this type of crystalline silicon solar cells: on the one hand, although the cost can be reduced by reducing the amount of silicon material used, with the reduction of the thickness of the silicon substrate, the use of traditional screen printing technology in its When metal electrodes are prepared on the surface, the fragmentation rate of the battery will increase due to mechanical reasons; on the other hand, although the recombination of minority carriers can be reduced by increasing the sheet resistance of the emitter and reducing the doping concentration of the emitter surface, however It is difficult to obtain the front metal grid line with low contact resistance by traditional screen printing technology, which limits the improvement of the photoelectric conversion efficiency of the battery

However, this technical solution involves two phosphorous diffusions. In addition, the groove technology is difficult to control, and it is easy to cause damage to the emitter.