Double-face growth silicon-based four-junction solar battery

The utility model discloses a double-face growth silicon-based four-junction solar battery. The double-face growth silicon-based four-junction solar battery comprises a Si sub battery as a substrate, a Ge sub battery disposed at the lower surface of the substrate, and a GaAs P sub battery and a GaIn P sub battery which are disposed at the upper surface of the substrate. The GaAs P sub battery and the GaIn P sub battery are connected with the Si sub battery through a GaAs P ingredient gradual change buffer layer, the Ge sub battery is connected with the Si sub battery through a Si Ge ingredient gradual change buffer layer, and the GaAs P sub battery and the GaIn P sub battery, the GaAs P sub battery and the Si sub battery, and the Si sub battery and the Ge sub battery are connected through tunnel junctions. According to the utility model, the cascade four-junction battery is prepared by use of the Si substrate, the band gap combination is about 1.95/1.5/1.12/0.67 eV, and at the time when the cost is decreased, the photoelectric conversion efficiency of the battery is also improved.