Superior stability of Sb-doped CdSeTe/CdTe devices

One of the primary activities in CdTe solar cell research is identifying an alternative to copper doping. Copper has limited solubility in the CdTe matrix, which restricts the achievement of higher open-circuit voltages (Voc). It is also a fast diffuser, making it a major contributor to device degradation. Finding a suitable alternative doping element could enhance Voc, improve cell efficiency, and increase stability. This study introduces a new approach for inserting Sb in CdSeTe/CdTe as a dopant: a thin Sb2Se3 layer is deposited on CdTe, and a CdCl2 treatment is used as a conveyor for Sb in the CdTe matrix. This simple and easy method proves to be effective, as Sb-doped cells achieve efficiencies comparable to those of Cu-doped cells. Furthermore, in accelerated stress tests without encapsulation, Sb-doped samples demonstrate much greater stability than Cu-doped cells, equivalent to undoped devices.