High-efficiency ion-implanted silicon solar cells

The development of solar cells with AM1 coversion efficiency of 18 percent is reported. The cells comprise an n
⁺
-p-p
⁺
structure fabricated from float zone silicon having resistivity of 0.3 Ω . cm. The n
⁺
and p
⁺
regions are formed by low energy ion implantation and thermal annealing. An important feature of cell fabrication is the growth of SiO
2
passivation for reduction of surface recombination velocity. Details of both cell fabrication and testing are reported.