Solar cell based on silicon substrate nanowire and preparing method thereof

The invention discloses a solar cell based on a silicon substrate nanowire. The solar cell comprises a back electrode, the silicon substrate, a diffusion structure layer, a nanowire array, a passivation layer and a front electrode which are sequentially in overlapping connection, wherein the silicon substrate is provided with a pyramid suede face, the diffusion structure layer is arranged on the pyramid suede face, the diffusion structure layer and the silicon substrate can form a PN knot, and the nanowire array is etched on the pyramid suede face. One nanowire comprises a bottom nanowire body and a top nanowire body, a doping type of the bottom nanowire body is identical with a doping type of the top nanowire body, and the doping density of the top nanowire body is higher than the doping density of the bottom nanowire body. The invention further discloses a preparing method of the solar cell. The nanowire array in the solar cell is of a hierarchical structure, the cell with the lower reflection rate can be obtained, the lengths of the nanowires are effectively reduced, passivation layer covering is facilitated, and the photon-generated carrier surface composite probability is reduced.