Solar cell and preparation method therefor

Abstract

In a solar cell, the back surface of a substrate thereof is provided with alternately distributed emitter zones and back surface field zones. An emitter is formed in each emitter zone, and the emitters are made of boron-doped monocrystalline silicon. A back surface field is formed in each back surface field zone; the back surface fields comprise tunneling oxide layers and polycrystalline silicon layers in stacked distribution, the polycrystalline silicon layers being made of phosphorus-doped polycrystalline silicon, and the tunneling oxide layers being located between a polycrystalline silicon layer and a polycrystalline silicon layer. Positive electrodes are electrically connected to the emitters, and negative electrodes are electrically connected to the back surface fields. In the described solar cell, the light-receiving area of the front surface can be expanded and the recombination rate of electron-hole pairs can be reduced, thereby effectively improving the photoelectric conversion efficiency of the solar cell.