Abstract: A wet etching method for an N-type bifacial cell including: (1) providing an N-type silicon wafer, proceeding with surface structuralization on the N-type silicon wafer, and producing a PN junction on a surface of the N-type silicon wafer by using a boron diffusion technique; (2) proceeding with a first mixed acid washing, etching the PN junction on an edge and a back surface of the N-type silicon wafer; (3) proceeding with a first pure water washing and a first alkaline washing, removing residual acid solution from the surface of the N-type silicon wafer; (4) proceeding with a second pure water washing and a second mixed acid washing, removing residual impurities from the surface of the N-type silicon wafer; (5) proceeding with a third pure water washing and air drying; and (6) after air drying, completing etching on the N-type bifacial cell.

Abstract: A high-efficiency N-type bifacial solar cell including: an N-type cell base including a structuralized surface; a P-type doped region formed on a front surface of the N-type cell base; a polished passivation layer formed on a back surface of the N-type cell base by etching; an N+ passivation layer formed by doping phosphorus into a top portion of the polished passivation layer adjacent to the N-type cell base; a first silicon dioxide layer formed on the P-type doped region and a second silicon dioxide layer disposed on the N+ passivation layer; a first silicon nitride antireflection layer formed on the first silicon dioxide layer and a second silicon nitride antireflection layer formed on the second silicon dioxide layer; and a first metal electrode formed on the front surface of the N-type cell base and a second metal electrode formed on the back surface of the N-type cell base.

Abstract: A wet etching method for an N-type bifacial cell including: (1) providing an N-type silicon wafer, proceeding with surface structuralization on the N-type silicon wafer, and producing a PN junction on a surface of the N-type silicon wafer by using a boron diffusion technique; (2) proceeding with a first mixed acid washing, etching the PN junction on an edge and a back surface of the N-type silicon wafer; (3) proceeding with a first pure water washing and a first alkaline washing, removing residual acid solution from the surface of the N-type silicon wafer; (4) proceeding with a second pure water washing and a second mixed acid washing, removing residual impurities from the surface of the N-type silicon wafer; (5) proceeding with a third pure water washing and air drying; and (6) after air drying, completing etching on the N-type bifacial cell.