Method for manufacturing silicon solar cell

Abstract

The invention discloses a method for manufacturing a silicon solar cell. In the process of manufacturing a PN junction on a silicon wafer, a selective diffusion technology method is adopted, i,e. laser is utilized to heat a position, on which a positive electrode intends to be manufactured, on the surface of the silicon wafer; and under the action of heating, phosphorus in a phosphorus source uniformly adhered on the surface diffuses towards the inner of the silicon wafer, thus a heavy doping zone with smaller sheet resistance is formed at the position on which the positive electrode intends to be manufactured to effectively reduce the sheet resistance of the silicon solar cell, thereby not only being beneficial for increasing the open-circuit voltage of the silicon solar cell; the increase of the open-circuit voltage effectively improves the conversion efficiency of the silicon solar cell, reduces ohmic contact of a metal electrode and the silicon solar cell, thereby reducing the series resistance of the silicon solar cell, and being capable of meeting the demand of industrialized production better.

Description

technical field [0001] The invention relates to a method for preparing a solar cell, in particular to a method for preparing a high-efficiency silicon solar cell. Background technique [0002] With the increasing shortage of conventional energy sources, renewable energy has attracted more and more attention from human beings. In the past 10 years, the amount of solar power generation has shown an exponential growth. With the continuous improvement of the preparation method of crystalline silicon solar cells, the production cost has been continuously reduced. , solar power generation will be more and more popular. [0003] At present, in the mass production process of silicon solar cells, due to the continuous upgrading of production equipment and the continuous improvement of new production and preparation methods, the production cost of silicon solar cells is further reduced, and the photoelectric conversion efficiency of cells is also continuously improved. New The prepar...

AI Technical Summary

Problems solved by technology

[0004] 1) In the process of making a semiconductor PN junction on a silicon wafer, it adopts the conventional diffusion process in the semiconductor industry to use phosphorus oxychloride (POCl 3 ) carry out high-temperature diffusion for the phosphorus source, and the n+ layer of the emission region formed in this way will increase the sheet resistance and dead layer of the silicon solar cell, thereby affecting the performance of the silicon solar cell;

[0005] 2) The de-edge junction process in this method is performed by inductively coupled plasma etching. Although the inductively coupled plasma etching method can also better remove the PN junctions around the silicon wafer that can cause front and back short circuits , but at the same time it also destroys the n+ layer in the emitter region, thereby reducing the performance of silicon solar cells;

[0006] 3), the coating silicon nitride thin film (ARC) process in this method has adopted the plasma enhanced chemical vapor deposition process, and it is mainly to deposit silicon nitride thin film on the positive surface of silicon wafer, so not only is unfavorable for silicon wafer The passivation of the back will also increase the generation of carriers on the back of the silicon wafer, which will affect the performance of silicon solar cells;

[0007] In addition to the shortcomings listed in the above-mentioned manufacturing method of crystalline silicon solar cells, the following defects generally exist in the existing solar cell manufacturing methods: in the existing manufacturing methods, the front and back electrodes are directly printed by screen printing technology, and the grid The line width is generally 120μ, and the line height is generally 25μ. Wider grid lines increase the shading area on the surface of the battery, which is extremely unfavorable for increasing the photogenerated current, thereby reducing the short-circuit current; In the previous chemical pretreatment process, the mixture of sodium hydroxide or potassium hydroxide, water and isopropanol is usually used to form a pyramid structure. Due to the high price of isopropanol, the production cost is also high