A kind of crystalline silicon solar cell and its preparation method

Abstract

In order to improve photoelectric conversion efficiency of a crystalline silicon solar cell, the invention provides a novel crystalline silicon solar cell includes a silicon substrate. The backlight face of the silicon substrate is provided with a conducting dielectric layer, a protection layer and a backlight face electrode grid line in sequence. The conducting dielectric layer is in contact with the silicon substrate. An aluminum back surface field is also arranged between the silicon substrate and the backlight face electrode grid line. The aluminum back surface field penetrates through the conducting dielectric layer and the protection layer and is in contact with the silicon substrate, the conducting dielectric layer and the backlight face electrode grid line. The conducting dielectric layer is made of P type zinc oxide. At the same time, the invention also discloses a preparation method of the above crystalline silicon solar cell. The photoelectric conversion efficiency of the crystalline silicon solar cell provided by the invention is high.

Description

technical field [0001] The invention relates to a crystalline silicon solar cell and a preparation method thereof. Background technique [0002] With the development of the solar industry and the intensification of competition, customers have higher and higher requirements for the efficiency of solar cells, and the entry threshold of the industry is also increasing. Therefore, it is necessary to explore more industrialization technologies to improve the conversion efficiency of solar cells. At present, the technology of solar cells to the light side is very mature, and the focus of improving the conversion efficiency is gradually shifting to the back side with great potential. With the help of atomic layer deposition (ALD) technology, the rear passivation battery with aluminum oxide passivation layer deposited on the back has become a bright spot at present. Passivated emitter and rear surface passivated cell (PERC) is mainly based on the good passivation effect of aluminum...

AI Technical Summary

Problems solved by technology

[0004] After depositing aluminum oxide and silicon nitride layers on the backlight surface of the silicon wafer, because the aluminum oxide and silicon nitride layers are poor conductors of electricity, even if the method of laser grooving is used to make the aluminum paste sinter and contact the silicon on the back surface to form a photo-generated carrier. However, due to the small area of ​​laser grooves and the poor lateral transport performance of photogenerated carriers, the series resistance of the battery increases and the fill factor decreases

On the other hand, after the aluminum oxide passivation layer is prepared, it is necessary to anneal the deposited passivation layer at a higher temperature to improve the effect of the passivation layer. In this process, the long-term high-temperature annealing process may cause Increased defect density in silicon wafers

In addition, the aluminum paste is printed on the entire area of ​​the silicon nitride protective layer. After sintering, the glass powder in the aluminum paste may corrode and penetrate the silicon nitride and The aluminum oxide layer causes the aluminum paste to damage the passivation layer, thereby weakening the effect of the passivation layer on improving the photoelectric performance of the battery to a certain extent

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