Crystalline silicon solar cell and preparation method thereof

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