Silk-screen printing production manufacturing method of passivated-back solar cell

Abstract

Provided is a silk-screen printing production manufacturing method of a passivated-back solar cell. The silk-screen printing production manufacturing method of the passivated-back solar cell comprises the steps that after texturing cleaning, high-temperature diffusion, secondary cleaning and front-surface silicon nitride deposition are carried out, passivation is carried out on the back surface of the solar cell through silicon oxide, passivation can also be carried out on the back surface of the solar cell through aluminum oxide or nitride silicon dioxide, and then a front electrode and a rear electrode of the solar cell are prepared completely in a silk-screen printing mode. A local contact electrode of the back surface is still prepared in a silk-screen printing mode, a used screen printing forme needs to be redesigned, the concentration of aluminum in used silver-aluminum sizing agents is high, and the silver-aluminum sizing agents have a certain etching effect on passive film on the back surface. After silk-screen printing is accomplished, ohmic contact of the front electrode of the passivated-back solar cell is formed in the process of high-temperature co-firing, and local contact of the back surface is formed at the same time; meanwhile, the local contact electrode and a main electrode of the back surface are independent from each other, and are connected through aluminum film, and transmission of carriers is achieved.

Description

technical field [0001] The invention relates to a production and preparation method of a passivated solar cell on the back, in particular adopting an industrialized screen printing method to form a local contact back electrode on the back. Background technique [0002] In today's photovoltaic market, further innovation of technology and improvement of conversion efficiency have become the core of competition between various businesses and the key to the survival of solar cell manufacturers. [0003] At present, the preparation process of solar cells is generally based on p-type silicon (p-Si) as the substrate. After the texturing and cleaning, high-temperature phosphorus (P) diffusion is performed to prepare the emitter (pn junction), and silicon nitride is deposited after the second cleaning. Reflective and passivation films, and then screen-print the front and rear electrodes and co-fire them to form ohmic-contact front and rear electrodes. The back of the solar cell usua...

AI Technical Summary

Problems solved by technology

[0006] Among the three commonly used methods, the first method is to form the contact hole area first, which is likely to cause voids during the co-firing process (E. Urrejola, K. Peter, H. Plagwitz, etc., Understanding and Avoiding the Formation of Voids for Rear Passivated Silicon Solar Cells, 3 rd Workshop on Metallization for Crystalline Silicon Solar Cells report), this method is not conducive to forming a good ohmic contact, and the obtained solar cell series resistance is high, which suppresses the fill factor of the solar cell and reduces the conversion efficiency of the solar cell

To this end, the domestic Trina company proposed a new sintering method to achieve local contact (Changzhou Trina Solar Energy Co., Ltd., a sintering method to improve the filling performance of back passivated solar cells, patent application number: 201210140670.4), They used the method of "turning over the wafer" to change the filling performance of the slurry on the surface of the silicon wafer during the high-temperature sintering process. To ensure the performance of the solar cell after sintering, the transmission speed should not be too low, so this method is not easy to realize, and it has no essential effect on improving the filling type of the slurry

Although the other two methods can avoid the formation of holes to a certain extent, the process of laser etching the film layer is inconvenient to control on the one hand, and on the other hand, the electrodes formed are not conducive to the interconnection between solar cells. During production, the aluminum layer and the interconnection bar cannot form a good welding effect, which will reduce the performance of the solar cell module and even cause the module to fail

[0007] To sum up, the three commonly used back electrode preparation methods of back passivation solar cells are not conducive to the formation of good ohmic contact, which reduces the conversion efficiency of solar cells, or are not conducive to the realization of the same process in the production process of subsequent solar cell modules. Good welding of interconnecting strips will reduce the performance of solar cell modules, even if high solar cell conversion efficiency can be achieved, high solar cell module power cannot be achieved

Combined with the actual production requirements, compared with the commonly used screen printing methods at present, the operation procedures of these methods are complicated, which is not conducive to industrial control, and is also not conducive to the reduction of production costs.

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