Numerical analysis of interface properties effects in CdTe/CdS:O thin film solar cell by SCAPS-1D

This paper investigates the influence of the absorber/window junction properties, on performances of CdTe/CdS:O solar cell, using SCAPS-1D package. Considering the case of ideal interfaces, charges transport mechanisms across the solar cell configuration are dominated by the diffusion and thermionic emission theories. We have shown that, with about 50 nm thickness of the absorber surface layer (CdTe 1− x S x ) and Δ E c at the CdTe/CdS:O interface comprises in the range [− 0.17 eV; 0 eV], an efficiency of about 21.85% can be reached. On the other hand, we obtained 21.77% with interface states density ( N t ) in the range of 10 6 –10 11 cm −2 and a flat conduction band at absorber/window interface. Further simulations predict that reducing interface states and Δ E c at the absorber/window interface leads to the improvement of the cell efficiency. This improvement is also observed with the increase in the thickness of CdTe 1− x S x and CdTe layers up to some values. Efficiency as high as 21.75% was obtained with Δ E c of − 0.1 eV, N t less than 10 10 cm −2 and CdTe bulk absorber thickness of 1.3 µm.