Production method for full back electrode solar cells

Abstract

The invention relates to a production method for full back electrode solar cells. The production method includes the steps: 1, performing single-surface boron diffusion to form a P+ layer on the back of an N-type silicon wafer; 2, depositing a texturing mask layer on the P+ layer; 3, performing single-surface texturing; 4, preparing a front surface field on the illuminated surface of the silicon wafer by phosphorus diffusion; 5, removing the texturing mask layer and PSG (phosphosilicate glass); 6, preparing an SiO2 mask layer by thermal oxide growth; 7, slotting in the area of a back surface field on the back of the silicon wafer, wherein the depth of each slot is not less than the junction depth of a P-N plus the depth of the back surface field together; 8, printing a phosphorous doping agent with the height less than the slot depth H minus the P-N junction depth at the bottom of the slotting area; 9, forming N+ layers at the bottom of the slots by the aid of high-temperature diffusion; 10, removing PSG and the SiO2 mask layer; 11, preparing a passive film on each of the front and the back; 12, performing screen printing for metal electrodes; and 13, sintering. The production method for the full back electrode solar cells has the advantages that cell efficiency is improved greatly while production cost is reduced by the aid of height difference of a P+ area and an N- area, namely a matrix N area, and suitability for large-scale production is achieved.

Description

technical field [0001] The invention relates to a production method of an all-back electrode solar cell. Background technique [0002] The all-back-electrode battery launched by SunPower in the United States uses N-type silicon wafers, and the electrodes are all designed on the back of the battery to maximize the light-absorbing area on the front of the battery. The conversion efficiency of its mass production has reached about 23%, the highest in the laboratory. The efficiency reaches 24.2%, but SunPower's battery preparation process is complicated and costly, which has always been a bottleneck for mass production and promotion. Contents of the invention [0003] The technical problem to be solved by the present invention is to provide a production method of a full back electrode solar cell, which simplifies the process steps and reduces the production cost. [0004] The technical scheme that the present invention adopts to solve its technical problem is: a kind of produ...

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Problems solved by technology

[0002] The all-back-electrode battery launched by SunPower in the United States uses N-type silicon wafers, and the electrodes are all designed on the back of the battery to maximize the light-absorbing area on the front of the battery. The conversion efficiency of its mass production has reached about 23%, the highest in the laboratory. The efficiency reaches 24.2%, but SunPower's battery preparation process is complicated and costly, which has always been a bottleneck for mass production and promotion

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