Coating film process for metallurgical grade monocrystalline silicon solar cell double-layer anti-reflection film

Abstract

The invention relates to a coating film process for a metallurgical grade monocrystalline silicon solar cell double-layer anti-reflection film. The coating film process is characterized by comprising the following steps: performing vacuum pumping inside a reaction chamber of a coating machine; aerating ammonia gas and silicane for 15s to 20s, controlling the ammonia flow to be 6300sccm to 6400sccm and the silane flow to be 1400sccm to 1500sccm; performing first film coating; performing vacuum pumping inside the reaction chamber, aerating ammonia gas and silicane for 15s to 20s, controlling the ammonia flow to be 7100sccm to 7200sccmand and the silane flow to be 600sccm to 700sccm; performing second film coating; performing vacuum pumping inside the reaction chamber, and aerating N2 until the pressure reaches normal pressure. Proved by trial use, the coating film process combines advantages in various aspects of the silicon nitride film and reaches maximum advantage.

Description

technical field [0001] The invention relates to a coating process in the manufacture of metallurgical-grade single-crystal silicon solar cells, in particular to a double-layer anti-reflection film coating process for metallurgical-grade single-crystal silicon solar cells. Background technique [0002] The application of silicon nitride anti-reflection film on solar cells has been extremely extensive. It mainly plays two roles. One is to reduce the reflection of light and increase the absorption of light by the battery; the other is to increase passivation, and the effect of silicon nitride coating is directly Affect the minority carrier life of the silicon wafer after coating and the conversion efficiency of the cell. However, the passivation effect of the film layer and the two characteristics of anti-reflection light are contradictory. [0003] At present, the conversion efficiency of double-layer silicon nitride coatings on silicon wafers according to the domestic improv...

AI Technical Summary

Problems solved by technology

However, most domestic metallurgical-grade monocrystalline silicon solar cell coating processes use PECVD equipment to deposit a single-layer silicon nitride anti-reflection film. Because the impurity content and defects of metallurgical-grade monocrystalline silicon wafers are higher than those of improved Siemens method single-crystalline silicon wafers, resulting in The minority carrier lifetime of silicon wafers is low after coating, so the conversion efficiency of metallurgical grade monocrystalline silicon solar cells with single-layer silicon nitride anti-reflection coating is 0.15% to 0.2% lower than that of the improved Siemens method

The single-layer coating process has a poor passivation effect on metallurgical-grade monocrystalline silicon wafers, and the conversion efficiency of cells is low

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