A kind of preparation method of n-type back junction solar cell

Abstract

The invention discloses a preparation method of an N type back knot solar cell. The preparation method comprises the steps of: performing iron injection on a light receiving face of an N type monocrystal silicon wafer, performing high-temperature oxidation activation on the silicon wafer after the ion injection, performing boron diffusion on the shady face of the silicon wafer after the high-temperature oxidation activation, forming a passivation layer on the shady face of the silicon wafer and forming an anti-reflection film on the light receiving face of the silicon wafer, and forming electrodes of the solar cell. The preparation method of the N type back knot solar cell can improve photoelectric conversion efficiency of the solar cell.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a preparation method of an N-type back junction solar cell. Background technique [0002] Solar energy is the cleanest, most common and most potential energy. A solar cell, also known as a photovoltaic cell, is a semiconductor device that directly converts the sun's light energy into electrical energy through the photoelectric effect or photochemical effect. When sunlight shines on the solar cell, the p-n junction of the solar cell forms hole-electron pairs. Under the action of the electric field of the p-n junction, the photogenerated holes flow to the p region, and the photogenerated electrons flow to the n region. After the circuit is connected, a current is formed. In today's energy shortage situation, solar cells are a new type of energy with broad prospects. At present, solar cells made of N-type monocrystalline silicon wafers are increasingly showing their advantages...

AI Technical Summary

Problems solved by technology

[0019] Boron diffusion is an important part in the preparation of N-type back-junction solar cells. When boron tribromide is used for diffusion, since boron tribromide is a liquid source, its diffusivity is worse than that of a gaseous source, resulting in high doping concentration at the edge of the silicon wafer. However, the central doping concentration is low, and the uniformity is difficult to control. Boron diffusion has always been a difficulty in the doping of N-type silicon solar cells. Conventional diffusion is difficult to achieve low-concentration uniform doping, thereby reducing the photoelectric conversion efficiency of solar cells. And before conventional boron diffusion, a thicker mask needs to be made to prevent the phosphorus diffusion surface from being affected by boron diffusion. The process is more complicated, which increases the production cost of solar cells.

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