Year: 2025 | Month: December | Volume: 12 | Issue: 12 | Pages: 63-69
DOI: https://doi.org/10.52403/ijrr.20251208
Influence of van der Waals Interactions on the Structural and Electronic Characteristics of SnSe: A DFT-Based Analysis
Erik Bhekti Yutomo1, Suci Faniandari2
1,2Department of Physics, Faculty of Science and Mathematics, Diponegoro University, Semarang, 50275, Indonesia.
Corresponding Author: Erik Bhekti Yutomo
ABSTRACT
Layered SnSe has attracted substantial interest due to its promising electronic and thermoelectric properties, which are strongly influenced by its anisotropic crystal structure. In this study, we systematically investigate the effects of van der Waals (vdW) interactions on the structural and electronic properties of SnSe by comparing first-principles calculations performed with and without the DFT-D3 correction. Structural relaxation results show that the inclusion of vdW interactions slightly reduces the interlayer spacing and the lattice parameter a, while the intralayer Sn–Se bond lengths remain nearly unchanged, reflecting the dominance of covalent bonding within the layers. Electronic band structure calculations reveal that SnSe maintains its indirect band gap of approximately 0.56–0.57 eV in both cases, with negligible shifts in the valence band maximum and conduction band minimum. Furthermore, the projected density of states (PDOS) confirms that the dominant orbital contributions—Sn 5p and Se 4p in the valence band and Sn 5p in the conduction band—are unaffected by the vdW correction. These findings indicate that while vdW interactions are essential for accurately describing the structural geometry of layered SnSe, they have limited influence on its intrinsic electronic characteristics. This work provides valuable insights for future theoretical and experimental studies aimed at optimizing SnSe-based electronic and thermoelectric applications.
Keywords: SnSe; van der Waals correction; DFT-D3; electronic band structure; projected density of states; lattice parameters; first-principles calculation
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