Simulation Analysis Of Cd1-Xznxs/Sb-2(Se1-Xsx)3 Solar Cells With N-I-P Structure

In this work, the use of Cd1-xZnxS ternary compound as an alternative ETL layer to CdS in solar cells with FTO/ CdS/Sb2(Se1-xSx)3/spiro-OMeTAD/Au structure is evaluated for the first time. Numerical calculations on Sb2(Se1xSx)3 solar cells with CdS and Cd1-xZnxS as ETL layers are performed for comparison. Experimental data reported for CdS/Sb2(Se1-xSx)3 solar cell are reproduced with good agreement, thereby validating our model. A solar cell efficiency enhancement from 10.0% to 13.3% is found with the use of a Cd1-xZnxS layer with a Zn concentration of 0.4 and a thickness of 70 nm. The impact of defects at Cd1-xZnxS/Sb2(Se1-xSx)3 and Sb2(Se1-xSx)3/spiroOMeTAD interfaces and Sb2(Se1-xSx)3 bulk on solar cell behavior is evaluated. In particular, we found that defects at Cd1-xZnxS/Sb2(Se1-xSx)3 interface stand as the main limiting factor of this technology. Finally, an efficiency of 14.8% is demonstrated with the reduction of interface defects to values of about 1011 cm-2. Under this condition, more attention should be paid to reducing the effect of series and shunt resistances in order to increase solar cell efficiency from 14.8% to 17.4%.