Introduction of Sb in CDTE and its effect on CDTE solar cells

One approach to further increase the performance of CdTe cells is by increasing their open-circuit voltage from its current state-of-the-art levels of 830–850 mV, which could be accomplished by increasing the net doping concentration in CdTe. Antimony (Sb) is a group V element and suitable p-type dopant for CdTe because of its low ionization energy, low diffusion coefficient, and relative ease of incorporation into CdTe. In this paper, the effects of Sb doping in CdS/CdTe solar cells have been studied. Antimony was introduced in CdTe by diffusion. The effects of the diffusion parameters, and the excess Sb on the CdTe surface were investigated. The best results were obtained when the Sb heat treatment was carried out at 430°C for 25 minutes. The results indicate that Sb incorporation into CdTe can yield higher net hole carrier concentration, however, the Voc values obtained to-date remain in the 800–830 mV range.