Insights into the band gap anomalies of certain bismuth-based chalcogenides through ab initio calculations of structural and electronic properties

Abstract

Unlike other conventional metal chalcogenides, where the Perdew-Burke-Ernzerhof (PBE) functional tends to underestimate band gaps, bismuth (Bi) chalcogenides, particularly Bi selenides, exhibit a counterintuitive behaviour with band gap predictions that closely align with experimental results. In this study, we report this anomaly in the band gap prediction of specific Bi-based chalcogenides. The structures of these compounds are of significant interest because their electronic band gaps match well with the reported experimental results when using the PBE functional. This unexpected and counterintuitive deviation, observed in this class of materials, offers valuable insights for material scientists studying compounds in this category.

Keywords

• Chalcogenides
• PBE functional
• Electronic properties