Low resistivity: High lifetime single crystal silicon investigation

Results of recent studies at Spectrolab utilizing improved quality, low resistivity silicon material are presented. Crystal doping methods used include boron ion implantation, diborane gas, and elemental gallium doping. Nt/P solar cells were fabricated from these materials and then evaluated electrically, both beginning of life and after electron irradiation. Cells made from 0.17 ohm-cm Si:Ga material yielded the most impressive results, with open circuit voltages of 633 mV at 25C, AMO. This float zone grown material also proved stable under photon irradiation post electron irradiation.