Different look at S-p bonding orbital in CdS, with Zn and Se series gap investigations

The electronic characteristics of Cadmium sulfide (CdS) series Zn x Cd16-x S8Se8 and Cd16Se16-x S x are investigated. According to the calculations, barely 12% Zn (X = 2) in the form Zn2Cd14Se16 is required to maximize the gap. To properly evaluate the excited states, the generalized gradient approximation (GGA) and modified Becke-Johnson (mBJ) potentials are utilized in the computations. The parent compound CdS exhibits three distinct forms of crystal structures, with the hexagonal structure being remarkably stable under the GGA and mBJ functionals. The partial density of states around the Fermi level demonstrates that the system's electronic characteristics are determined by the interaction of S-p and Cd-s,p states. A substantial splitting of the valence band, shown by band structure analysis, suggests a greater polarization crystal field in the hexagonal CdS structure. The stereochemical activity of the S atom stimulated the CdS compound for extremely tiny displacements of 0.0014 angstrom and 0.043 angstrom for the Cd and S atoms in the [001] direction, respectively, as well as tilting of the Cd-S-Cd link. This compound exhibits lone pair properties, with three valance electrons of the p-orbital participating in covalent bonding and S-s electrons fully occupied. Furthermore, Van Hove singularities are discovered in the electron density of states due to the Cd-d atoms that support in the analysis of optical absorption spectra. Finally, the results suggest that CdS has potential for solar cells applications due to its direct wide band gap semiconductor features,

Automated summary

The electronic characteristics of CdS series compounds ZnxCd16-xS8Se8 and Cd16Se16-xSx are investigated. The addition of 12% Zn (X=2) is found to maximize the gap in the Zn2Cd14Se16 form. The interaction between S-p and Cd-s,p states determines the electronic characteristics of CdS. The hexagonal CdS structure exhibits a greater polarization crystal field and lone pair properties. The results suggest the potential application of CdS in solar cells due to its wide band gap semiconductor features.