Ultrathin CdTe Solar Cells with MoO3-x/Au Back Contacts

We report on the fabrication and characterization of CdTe thin-film solar cells with Cu-free MoO3-x /Au back contacts. CdTe solar cells with sputtered CdTe absorbers of thicknesses from 0.5 to 1.75 mu m were fabricated on Pilkington SnO2:F/SnO2-coated soda-lime glasses coated with a 60- to 80-nm sputtered CdS layer. The MoO3-x /Au back contact layers were deposited by thermal evaporation. The incorporation of MoO3-x layer was found to improve the open circuit voltage (V (OC)) but reduce the fill factor of the ultrathin CdTe cells. The V (OC) was found to increase as the CdTe thickness increased.