Patent ID: 8163638

Claim:
A method of forming active diffusion regions in a back side contact solar cell, the method comprising: providing a wafer to be processed into a solar cell, a front side of the wafer being configured to face the sun during normal operation of the solar cell; selectively depositing P-type dopant sources and N-type dopant sources on a back side of the wafer, the back side being opposite the front side of the solar cell, the P-type and N-type dopant sources being selectively deposited by inkjet printing them on the back side of the wafer, the N-type dopant sources being selectively deposited overlapping the P-type dopant sources and on exposed portions on the back side of the wafer not covered by the P-type dopant sources; and performing a diffusion step to diffuse dopants from the P-type dopant sources to form P-type active diffusion regions of the solar cell and dopants from the N-type dopant sources to form N-type active diffusion regions of the solar cell.