Preparation method for efficient crystal silicon passivated emitter rear contact (PERC) solar cell

Abstract

The invention discloses a preparation method for an efficient crystal silicon passivated emitter rear contact (PERC) solar cell. The production method comprises the steps of providing a silicon wafer, and forming a textured surface on the front surface of the silicon wafer; forming a phosphorus diffusion layer on the front surface of the silicon wafer, and then removing PSG and peripheral phosphorus diffusion layer on the front surface of the silicon wafer; forming an SiNx antireflection layer on the front surface of the silicon wafer; forming an AlOx passivation layer on the back surface of the silicon wafer; forming an SiNx protection layer on the back surface of the silicon wafer; windowing the silicon wafer by a laser, wherein the laser windowing process is completed in two times; and implementing silk-screen printing on the silicon wafer. Correspondingly, the invention also provides the efficient crystal silicon PERC solar cell, which is prepared by using the preparation method provided by the invention. The preparation method provided by the invention is simple in technology and low in cost, and the acquired crystal silicon PERC solar cell is high in efficiency and good in appearance.

Description

technical field [0001] The invention relates to the field of solar cell manufacturing, in particular to a method for preparing high-efficiency crystalline silicon PERC cells. Background technique [0002] Crystal silicon PERC cells refer to Passivated emitter rear contact solar cells. Back passivation technology is an important technical means to realize high-efficiency polysilicon cells, and its main technical feature is to coat a layer of passivation film on the back of solar cells. Because the fixed negative charge density inside this layer of passivation film is high, it has a good field passivation effect, and the recombination rate of carriers on the back of the battery is reduced, which can effectively improve the minority carrier lifetime of crystalline silicon cells, thereby improving the photoelectricity of crystalline silicon cells. conversion efficiency. [0003] With the continuous development of science and technology and the upgrading of equipment, the prepa...

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Problems solved by technology

The use of plate PECVD, although it can solve the front SiN x The problem of poor film uniformity and unstable optical properties, but the low production capacity of plate PECVD, high equipment cost and maintenance cost are also serious problems that need to be faced

[0005] Another issue that affects the cell efficiency of back passivated cells is the high series resistance of back passivated cells

At present, the single laser process has the following problems: 1) Since the energy of the laser source is Gaussian distributed, the ablation effect at the edge of the laser window will be lower than that in the center area. In order to avoid the ablation depth in the center area being too deep, the edge of the window area Silicon nitride is easy to remove and incomplete; 2) The energy range used for laser window opening is small: if the energy used is too high, the surface of the silicon wafer will be damaged and a carrier recombination center will be formed; if the energy used is too low, the back side will be passivated 3) The line width of a single laser is narrow: limited by the laser source itself, the width of a single laser window is generally not greater than 50 μm. In order to achieve a good ohmic contact on the back of the battery, it is necessary to properly The ratio of window opening leads to further narrowing of the laser line spacing, which will also lead to increased damage on the silicon surface

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