The Influence Of Minority Carrier Lifetime Of The N-type Monocrystalline Silicon On Efficiency Of Crystalline Silicon Cells

With the rapid development of photovoltaic industry,high-efficiency silicon solar cells have become a hot research in recent years.The most remarkable event is that the conversion efficiency of N-type monocrystalline cells was as high as 25.6%created by the Panasonic,refreshing the record in the crystalline silicon solar cells.The large area of 143.7cm~2 provided the possibility to realize industrialization.Therefore,compared to P-type silicon solar cells with serious light-induced degradation,N-type monocrystalline silicon cells have more broad application prospects.In the paper,the relationship of the minority carrier lifetime and the conversion efficiency of the N-type monocrystalline silicon has been studied.Firstly,argon flow fields in regular heating system and improved heating system of N-type monocrystalline silicon crystal growth were simulated using finite element method.The results showed that the improved heating system could improve the stability of the crystal growth environment.When the argon velocity was 0.6 m/s,the minimum oxygen concentration was obtained in N-type monocrystalline silicon which was beneficial to preparing the higher minority carrier lifetime of monocrystalline silicon.It is also shown that the yield rate of the silicon prepared by TD90A furnace with improved heating system was as high as 80%.Secondly,the performance of the N-PERC solar cells was simulated by PC1D.The influence rules of minority carrier lifetime and resisitivity of silicon wafers,the sheet resisitance and the junction depth of the emitter on the output performance of solar cells were obtained.Finally,the influence of minority carrier lifetime and lifetime radical non-uniformity on the efficiency of N-PERC monocrystalline silicon cells was studied.The results showed that when the minority carrier lifetime of silicon wafers was less than 700?s,the conversion efficiency of solar cells was improved significantly as the increasing of minority carrier lifetime.When the minority carrier lifetime of silicon wafers was more than 700?s,the conversion efficiency of solar cells was increased slightly and was determined by the minority carrier lifetime and the lifetime radical non-uniformity.