| 摘要 |
<p>The present invention relates to the technical field of the production of solar cells, especially to an impurity gettering process for polysilicon. The silicon wafers firstly undergo a high temperature phosphorus diffusion gettering treatment to dissolve impurities of the metal precipitates and of the metallic composite in silicon. Subsequently the wafers undergo a low temperature phosphorus diffusion gettering treatment, through the differences of the impurity segregation coefficients in different regions, to effectively diffuse the impurity atoms into the phosphorus diffusion region and to get a uniform diffusion region. Through the impurity gettering process, the silicon wafers are more purified, which provides a better basis for the following fabrication of the solar cells and may greatly improve the transform efficiency of the final solar cells.</p> |
