A thermal dynamical boron getter (pp+ getter) in Fe-contaminated mass production of the boron diffused n+pp+ BSF bifacial silicon solar cells

Thermal dynamical treatment for improving the lifetime of the p base of n+pp+ BSF bifacial silicon solar cells have been demonstrated using iron behavior parameters called pp+ getter. [1]∼[10] The SIMS for the wafers in the mass production showed a precipitated high concentration of iron region near the surface of the boron diffusion layer, and the phosphorus diffusion layer respectively. A high temperature treatment suppose to increases iron in the p base by diffusing interstitially from the precipitated region, and low temperature treatment decreases the iron over the solubility diffusing to the precipitated region. So, the last thermal treatment needs long time and the low temperature enough for improving the lifetime. The simulations and examinations on the changes of the lifetime through the cell process showed good consistency.