Front surface grid-line-free P type crystal silicon back contact two-sided battery structure and manufacturing method therefor

Abstract

The invention discloses a front surface grid-line-free P type crystal silicon back contact two-sided battery structure and a manufacturing method therefor. A transparent conductive film is positioned on a front surface passivation film and an antireflection film; via hole electrodes used for connecting front surface and back surface negative electrodes of the battery are arranged in through holes in a P type crystal silicon wafer; partial heavily-doped N+ regions distributed based on regular patterns are arranged on the surface layer of an N type layer; the transparent conductive film passes through the antireflection film and the front surface passivation film to be in electrical contact with the partial heavily-doped N+ regions and the top ends of the via hole electrodes to form a battery negative electrode; the transparent conductive film is used for guiding electrons collected on the front surface of the battery to the back surface of the battery through the via hole electrodes; and back surface positive electrode thin grid lines pass through a first back surface passivation film and a second back surface passivation film to form partial ohmic contact with a P type substrate and to be connected with back surface positive electrode main grid lines together to form a battery positive electrode. By virtue of the battery structure and the manufacturing method therefor, light shielding of the battery positive electrode is avoided, power output is increased, consumption amount of silver paste in the battery manufacturing process is reduced, and production cost is lowered.

Description

technical field [0001] The invention belongs to the technical field of solar cells, and in particular relates to a P-type crystalline silicon back-contact double-sided cell structure and a manufacturing method without front grid lines. Background technique [0002] Since the first solar cell was born in Bell Laboratories in 1954, crystalline silicon solar cells have been widely used, the conversion efficiency has been continuously improved, and the production cost has continued to decline. At present, crystalline silicon solar cells account for more than 90% of the global market for solar cells, and the conversion efficiency of crystalline silicon cell production lines has exceeded 21%. The cost of electricity continues to shrink and is expected to be flat in the next few years. As a clean energy source, crystalline silicon solar cells play an increasingly important role in changing the energy structure and alleviating environmental pressure. [0003] Due to the mature pro...

AI Technical Summary

Problems solved by technology

Although the MWT battery technology reduces the light-shielding area of ​​the main grid electrode on the front of the battery, the thin grid lines on the front of the battery still have about 3% of the light-shielding area. The thin grid lines are usually made of expensive silver, which is important for reducing the production cost of the battery sheet. unfavorable

In addition, the leakage problem of MWT battery has not been solved well

The above problems make MWT, as the core technology for improving the front of the battery, has not been applied on a large scale.

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