Theoretical calculations of structural, electronic, excitonic and optical properties of N-doped Sb2S3 are studied using highly accurate first-principles approach within many-body perturbation theory (MBPT) formalism. The calculated structural parameters of undoped Sb2S3 within Wu-Cohen's generalized gradient approximation (WC-GGA) are reasonably close to those obtained in experimental measurement. Many-body perturbation theory (MBPT) based on the G0W0 approximation is used for the quasiparticle (QP) band structure. The bandgap value of 1.70 eV for the undoped Sb2S3 crystal within G0W0 approximation is consistent with the experimental value of 1.70?1.80 eV. When one atom of N is introduced into Sb2S3 at Sb site, the doping effects modified the band gap from 1.70 to 1.17 eV. Also, by introducing one atom of N to S site, the band gap value reduced to 0.96 eV. Our findings confirmed that non-metal doping narrow the energy gap of semiconductor materials. The optical properties of pure and N.....

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Cadmium telluride (CdTe) solar cells have attracted a lot of interest in recent years, attributed to their low cost and eco-friendly fabrication technique. However, the back contact is still the key issue for further improvement in device performance due to the work function difference between p-CdTe and metal contacts. In this study, the interatomic characteristics of zinc telluride (ZnTe) and Cu-doped ZnTe (ZnTe:Cu) as a back surface field (BSF) in CdTe structure is investigated using first-principles density functional theory (DFT) to overcome the Schottky barrier in CdTe solar cells. The incorporation of different doping levels of copper (Cu) in ZnTe on an atomic scale, where Zn1−xTe:Cux (x = 0, 2, 4, 6, 8, and 10) as the potential back surface field layers is investigated. The effect of doping concentration on electrical characteristics such as bandgap structure and density of states (DOS) were examined via ab initio with the Hubbard U (DFT + U) correction. The results showed an.....

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