First principles study of the influence of metallic-doping on crystalline ZnS: From efficiency aspects for use in a ZnS based dye sensitized solar cell (DSSC)

In the framework of Density Functional Theory (DFT), we examined the influences of metallic X dopants (X = Mg, Ca, Mn, Fe, Ni, Co, Cu) on the electronic structure of ZnS. The photovoltaic behaviour of the ZnS based dye sensitized solar cell (DSSC) is directly affected by the modification in the electronic structure and surface defects due to doping. We have done a comparative study of the effects of various dopants on the efficiency of the ZnS based DSSC based on the combined effects of electronic structure and surface defects. We observed a reduction in the band gap of ZnS for the transition metal dopants including Mn, Fe, Ni, Co and Cu. On the other hand we recorded an increase in the band gap of ZnS for Mg and Ca dopants indicating that these dopants must be avoided if we want to use ZnS in a DSSC.