Studies of implanted boron emitters for solar cell applications

B implanted emitters are investigated in the back junction cell configuration and their material properties are tested in double side implanted Si wafers. B has been implanted at 5 keV at various dose conditions varying from 1 × 10¹⁴ up to 3 × 10¹⁵ at./cm² and activated at 1000°C for 10 min. N‐type 8 × 8 cm² mono‐crystalline cells are fabricated and measured. Both fill factor and efficiency increase for high‐B doses. However, at 10¹⁵ at./cm² B dose the V_oc drops, which is in agreement with lifetime degradation in the wafer. Defect evolution simulations of B_nI_m clusters formation is correlated with lifetime degradation. Copyright © 2011 John Wiley & Sons, Ltd.