Dependence of efficiency of thin-film CdS/CdTe solar cell on parameters of absorber layer and barrier structure

Abstract Dependences of the open-circuit voltage, short-circuit current, fill factor, and efficiency of a CdS/CdTe solar cell on the resistivity and thickness of the p-CdTe absorber layer, the noncompensated acceptor concentration N a – N d, and carrier lifetime τ in CdTe, are investigated, and optimization of these parameters in order to improve the solar cell efficiency is performed. It has been shown that the observed low efficiency of CdS/CdTe solar cells is caused by the too short electron lifetime in the range of 10 − 10 –10 − 9 s and too thin (3–5 µm) CdTe layer currently used for fabrication of CdTe/CdS solar cells. To achieve an efficiency of 28–30%, the resistivity and thickness of the CdTe absorber layer, the noncompensated acceptor concentration, and carrier lifetime should be ∼ 0.1 Ω·cm, ≥ 20–30 µm, ≥ 10 16 cm − 3 , and ≥ 10 − 6 s, respectively.