The invention discloses a broad-spectrum absorption
black silicon solar cell structure. The structure sequentially comprises an irradiated face
broad spectrum light
trapping layer, a p-shaped
silicon substrate, a n-shaped phosphorous
diffusion layer and a backlight surface broad-spectrum absorption
black silicon layer from top to bottom. The invention simutaneously discloses a preparation method of the broad-spectrum absorption
black silicon solar cell structure. In the invention, the characteristics of the black
silicon material can be fully utilized to enable sunlights entering into the
cell to be almost absorbed; simutaneously a back
dopant gradient can be utilized to separate eletron-hole pairs generated in the black
silicon by a self-configuration
field separation method, so that the eletron-hole pairs can be received and transfomred into light current by electrodes, thereby solving the problem that the traditional silicon substrate
cell can not absorb and transform solar spectrum of which the
wavelength is above 1.1 microns; and the PN junction of the structure is formed by diffuse junctions, the open-circuit
voltage of the
cell can be ensured not to be influenced by lowered black silicon lower-energy
photon conversion, thereby effectively improving the
photoelectric conversion efficiency of the silicon substrate sollar cell.