Effect of metal impurities concentration on electrical properties in N-type Recharged-Czochralski silicon

The electrical properties of N-type Recharged-Czochralski (RCz) silicon solar cells are significantly affected by the concentration of metal impurities in the silicon materials. In this work, several N-type RCz silicon ingots were grown using feedstock with different impurities concentration, and the distribution of minority carrier lifetime was tested. It was discovered that a broader range of feedstock impurity concentrations resulted in high and stable minority carrier lifetime of the ingots. Solar cells made from these ingots had an average efficiency of over 24.57%. Meanwhile, the results of impurities segregation calculation and solar cells electroluminescence(EL) test were given. The results indicated that ring defects were the primary cause of differences in electrical properties among silicon ingots produced from feedstock with varying impurity concentrations. Further, the process win-dow to produce high efficiency N-type Czochralski(Cz) silicon solar cells was broadened, and the production cost could be reduced.

Automated summary

The electrical properties of N-type Recharged-Czochralski (RCz) silicon solar cells are significantly affected by the concentration of metal impurities in the silicon materials. In this study, several N-type RCz silicon ingots were grown using feedstock with varying impurities concentration, and the distribution of minority carrier lifetime was tested. It was found that a wider range of impurity concentrations in the feedstock led to higher and more stable minority carrier lifetime in the ingots. Solar cells made from these ingots achieved an average efficiency of over 24.57%. Additionally, impurities segregation calculation and solar cells electroluminescence (EL) test results suggested that ring defects were the primary cause of variations in electrical properties of silicon ingots produced from feedstock with different impurity concentrations. This study broadened the process window for producing high-efficiency N-type Czochralski (Cz) silicon solar cells, potentially reducing production costs.