Technology capable of lowering reject ratio of appearance of anti-PID battery

Abstract

The invention discloses a technology capable of lowering the reject ratio of the appearance of an anti-PID battery, which is mainly used for reducing the poor appearance caused by an anti-PID battery slice prepared by an ozone oxidization method. The method comprises the following steps: growing a silicon dioxide film on a textured, diffused and etched silicon wafer by the ozone oxidization method; putting the silicon dioxide film into a graphite boat deposited with a silicon nitride film; putting the graphite boat into a plasma vapor deposition furnace tube, pumping vacuum until 10Pa and heating the graphite boat to 350-450 DEG C; filling the tube with a nitrogen gas or an ammonia gas or a mixed gas of the nitrogen gas and the ammonia gas, keeping the air pressure at 230Pa, starting an excitation source and pre-cleaning an oxidation film on the surface of the silicon wafer for a period of time; pumping vacuum again, introducing the ammonia gas and silane, carrying out silicon nitride film deposition; and taking out the silicon wafer deposited with the silicon nitride film from the graphite boat. The technology effectively reduces the poor appearance caused by the anti-PID battery slice prepared by the ozone oxidization method, and does not affect the anti-attenuation effect of the battery slice.

Description

Technical field: [0001] The invention relates to the field of solar cells, in particular to a process capable of reducing the appearance defect rate of anti-PID cells. Background technique: [0002] The phenomenon of potential-induced decay (PID) was first discovered by Sunpower in 2005. The long-term high voltage of solar cell components causes leakage current between glass and packaging materials, and a large amount of charge accumulates on the surface of the cell, which makes the cell surface passivation. The effect deteriorates, resulting in a decrease in open circuit voltage, short circuit current and fill factor, making the performance of the component lower than the design standard. [0003] The method to prevent this phenomenon is to increase the refractive index of the silicon nitride film, or to grow a silicon dioxide film between the silicon nitride and the silicon substrate by thermal growth or plasma vapor deposition. The refractive index of silicon nitride wil...

AI Technical Summary

Problems solved by technology

[0002] The phenomenon of potential-induced decay (PID) was first discovered by Sunpower in 2005. The long-term high voltage of solar cell components causes leakage current between glass and packaging materials, and a large amount of charge accumulates on the surface of the cell, which makes the cell surface passivation. The effect deteriorates, resulting in a decrease in open circuit voltage, short circuit current and fill factor, making the component performance lower than the design standard

[0003] The method to prevent this phenomenon is to increase the refractive index of the silicon nitride film, or to grow a silicon dioxide film between the silicon nitride and the silicon substrate by thermal growth or plasma vapor deposition. The refractive index of silicon nitride will lead to a decrease in cell efficiency. The thermal growth method and the plasma vapor deposition method will damage the silicon wafer and the graphite boat respectively. Although the recent method of using ozone oxidation has solved the shortcomings of the above methods, And the cost is low, but because of the plasma-assisted deposition of silicon nitride after the process, the appearance of surface fog spots will occur, and the occurrence rate is between 5% and 50%, which will affect the product quality.