Solar cell, its module and its manufacturing method

Abstract

The present invention provides a solar cell, a module thereof and a manufacture method thereof. The cell comprises a substrate possessing a right side and a back side, an emitter layer arranged on the right side, and a passivation layer arranged on the back side, an opening arranged on the passivation layer in an extension and bending manner, and a backside electrode arranged on the passivation layer and contacted with the back side via the opening. The projection area of the opening on the back side is 3% to 12% of the area of the back side. The present invention also provides another cell which comprises a plurality of annular openings surrounding annularly from inside to outside. By the design of the continuously extending and bending single opening or the plurality of annular openings, the current collection effect of the backside electrode can be enhanced. Moreover, a back electric field structure formed by sintering is enough in thickness and good in quality, thereby improving the photoelectric conversion efficiency of the cell.

Description

technical field [0001] The invention relates to a solar cell, its module and its manufacturing method, in particular to a silicon crystal solar cell, its module and its manufacturing method. Background technique [0002] refer to figure 1 , figure 2 , the known silicon solar cell mainly includes: a substrate 91 having an opposite front surface 911 and a back surface 912, a plurality of local back surface field structures (Local Back Surface Field, LBSF for short) 92 located on the back surface 912, a A passivation layer 93 on the back surface 912, a plurality of linear openings 94 on the passivation layer 93, a back electrode 95 on the passivation layer 93, at least one on the passivation layer 93 and The bus electrode 96 contacts the back electrode 95 and a front electrode 97 on the front surface 911 of the substrate 91 . [0003] The passivation layer 93 is used to repair and reduce surface defects of the substrate 91 , thereby reducing the recombination rate of carrie...

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Problems solved by technology

[0007] The problem of the above-mentioned passivation layer 93 material remaining at the end of the linear opening 94 will affect the contact between the back electrode 95 and the substrate 91, and then make the current collection performance worse, because the back electrode 95 is screen printed. The conductive paste will be disturbed by the residual material of the passivation layer 93, so it is difficult to completely fill the end points of the linear openings 94, which will cause the Al-Si alloy formed by mixing the conductive paste material and the substrate 91 material The thickness of the back electric field structure (BSF) 92 is thinner, and then the thickness of the back electric field structure (BSF) 92 formed by subsequent sintering is thinner and the quality is poor, and thus the function of the back electric field structure 92 is damaged, thereby causing a decrease in the open circuit voltage and short circuit current, and making the The conversion efficiency of the battery deteriorates

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