Solar cells made from p-CdTe films grown with ion-assisted doping

CdTe thin films grown by ion-assisted doping are investigated for use as the absorber layer in solar cells. In particular, the sharp reduction in carrier density with increased ion current which occurs after a maximum in the carrier density has been reached is examined. The ability to make carrier density profiles and to grade junctions is demonstrated. Preliminary results from films grown on graphite and alumina substrates are presented. Solar cells prepared using the epitaxial p-CdTe films as the collector material and n-CdS as the window are presented, and V_oc, J_sc, and fill factor are examined for different carrier densities and configurations in the p-CdTe. Carrier density levels in p-CdTe epitaxial films up to 2*10¹⁷ cm^-3 using ion-assisted doping with P as the dopant were achieved.