Analysis of Hole Transport Layer and Electron Transport Layer Materials in the Efficiency Improvement of Sb₂(Se_1−xS_x)₃ Solar Cell

Sb₂(Se_1−xS_x)₃ compounds have been regarded as an excellent absorber in thin film solar cells processing. At present, the best efficiency reported in these chalcogenides of antimony corresponds to FTO/CdS/Sb₂(Se_1−xS_x)₃/Spiro-OMeTAD/Au structure with 10.5%. Herein, a comparative study on the Sb₂(Se_1−xS_x)₃ solar cell performance with different electron transport layers (ETLs) and hole transport layers (HTLs) is carried out. The main photovoltaic parameters such as short-circuit current density, open-circuit voltage, fill factor, power conversion efficiency, and external quantum efficiency of devices with n–i–p structures are analyzed from a theoretical point of view. The impact of different ETL, HTL, and absorber thicknesses as well as the influence of Sb₂(Se_1−xS_x)₃ bulk and interface defects on the final efficiency of the device is investigated. After the optimization of the above physical parameters, it is demonstrated that with the FTO/ETL/Sb₂(Se_1−xS_x)₃/HTL/Au proposed structure, efficiency can be improved from 10% to 16%. In particular, it is found that Cd_0.6Zn_0.4S and ZnO are better candidates for ETL, while the use of NiO and Cu₂O as HTL results in increased efficiencies in comparison to the traditional Spiro-OMeTAD.