Electron Density and Optoelectronic Properties of Copper Antimony Sulphur Ternary Compounds for Photovoltaic Applications

Mohamed Khairy (1) , Pingping Jiang (2, 3) , Pascal Boulet (2) , Marie-Christine Record (3)

1 Sohag University
2 MADIREL - Matériaux divisés, interfaces, réactivité, électrochimie
3 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence

Design of efficient solar energy-conversion materials has attracted much interest in the last decades. Among these materials, copper-based semiconducting chalcogenides have been employed as alternatives for copper indium gallium selenide (CIGS) thin-film solar cells due to their low toxicity and earth-abundant absorber components. In the present manuscript, structural, electronic, topological, and optical properties of ternary chalcogenide CuSbS2, Cu3SbS3, and Cu3SbS4 have been investigated using the full potential linear augmented plane wave (FP-LAPW) method. An indirect bandgap is observed for CuSbS2 with Eg = 1.178 eV and a direct bandgap is found for Cu3SbS3, and Cu3SbS4 with Eg = 1.283 and 1.0 eV, respectively. The valence band maximum (VBM) of CuSbS2, Cu3SbS3, and Cu3SbS4 are mainly predominated by a strong Cu-3d and S-3p orbitals hybridization. The conduction band of CuSbS2 and Cu3SbS3 are mainly characterized by Sb-5p orbital and S-3p orbital mixing. However, conduction band of Cu3SbS4 is dominated by the mixing of Sb-5s and S-3p orbitals. It is found that the Cu-S and Sb-S bonds lie in the transit closed-shell zone, between the typical ionic and covalent bonds. The optical properties of CuSbS2, Cu3SbS3, and Cu3SbS4 in terms of absorption coefficient, extinction coefficient, refractive index, and reflectivity have been investigated. The results show that the CuSbS2, Cu3SbS3, and Cu3SbS4 compounds have real potential to be used for solar-energy conversion.

Mots clés: Copper-based chalcogenides; DFT; optoelectronic properties; electron density topology; solar-energy conversion

Domaines: Chimie

Mohamed Khairy, Pingping Jiang, Pascal Boulet, Marie-Christine Record. Electron Density and Optoelectronic Properties of Copper Antimony Sulphur Ternary Compounds for Photovoltaic Applications. Journal of Electronic Materials, 2022, 51 (7), pp.3903-3918. ⟨10.1007/s11664-022-09650-3⟩. ⟨hal-03983411⟩