Structural and electronic properties of SnS2 stacked nanosheets: An ab-initio study H.B. Mabiala-Poatya,b,∗, D.H. Doumaa,b, B. M'Passi-Mabialaa,b, R.E. Mapashac aGroupe de Simulations Numériques en Magnétisme et Catalyse (GSMC), Faculté des Sciences et Techniques, Université Marien Ngouabi, BP 69, Brazzaville, Congo bUnité de Recherche en Nanomatériaux et Nanotechnologies, Institut National de Recherche en Sciences Exactes et Naturelles (IRSEN), Brazzaville, Congo cDepartment of Physics, University of Pretoria, Pretoria, 0002, South Africa
A R T I C L E I N F O
Keywords: DFT Nanosheets VanderWaals exchangecorrelation functionals Electronic structure 2D materials SnS2
We present an ab-initio study of the structural and electronic properties of SnS2 stacked nanosheets using the standard LDA andGGAfunctionals aswell asthe newly developedvariants ofthe non-local vanderWaals(vdW) exchange correlation functionals, namely vdW-DF-revPBE and vdW-DF2-C09. We have examined diﬀerent stacking conﬁgurations of the two, three and four SnS2 layers. The GGA-PBE functional fails to describe the interlayer binding energies and interlayer spacing of SnS2 nanosheets, while a good agreement is observed between the calculated and available experimental values when the van der Waals corrected functionals are used, mostly the vdW-DF2-C09. It is found that the interlayer interactions in the SnS2 ﬁlms are not only vdW type but, the overlap of wave functions of neighboring layers have to be taken into account. We have observed a systematic reduction in the band gap with the increase in the number of stacked layers.