Boron implanted, laser annealed p+ emitter for n-type interdigitated back-contact solar cells

Ion implantation and laser processing technologies are very attractive for the fabrication of industrially feasible interdigitated back-contact (IBC) solar cells. In this work, p+ emitters were fabricated by boron implantation and laser annealing, and the electrical properties of emitters were investigated. An emitter sheet resistance (Rsh) in the range of 30-200 O/OS could be achieved by varying the implanted dose. The saturation current density (Joe) of the passivated p+ emitter with Rsh of ∼125 O/OS reached 95 fA/cm2, and the contact resistivity was determined to be as low as 5×10-6 O·cm2. Such localized p+ emitters can be applied to n-type IBC solar cells, which could avoid the high temperature thermal annealing step and related problems.