The influence of He+ implantation on the properties of crystalline sil
icon solar cells has been investigated. The implantation of 550 keV He
+ ions into the masked surface of solar cells was used to form a two-d
imensional defect layer inside the cell space-charge region. For suita
ble implantation doses it is possible to increase the photocurrent wit
hout degenerating the values for open circuit voltage thus resulting i
n an improved efficiency of the cells.