First-principles study of $$\hbox {SiO}_2$$/$$\hbox {MoS}_2$$ and $$\hbox {SiO}_2$$/$$\hbox {WS}_2$$ interfaces: A comparative analysis of surface terminations, van der Waals corrections, and functionals

Abstract This study presents a first-principles investigation of $$\hbox {SiO}_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>SiO</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> </mml:math> / $$\hbox {MoS}_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>MoS</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> </mml:math> and $$\hbox {SiO}_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>SiO</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> </mml:math> / $$\hbox {WS}_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>WS</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> </mml:math> interfaces, examining how surface terminations, van der Waals (vdW) corrections, and functional choices impact structural stability and electronic properties. Using density functional theory with generalized gradient approximation (GGA; PBE, PBEsol, revPBE), meta-GGA (SCAN, $$\hbox {r}^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mtext>r</mml:mtext> <mml:mn>2</mml:mn> </mml:msup> </mml:math> SCAN), and hybrid (PBE0) functionals, we assess the effect of vdW correction schemes (D2, D3, Tkatchenko-Scheffler) on interfacial energetics and separation. The results show that vdW corrections are essential for accurate GGA descriptions, while meta-GGAs yield similar accuracy even without them, enabling efficient modeling of $$\hbox {SiO}_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>SiO</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> </mml:math> /2D heterostructures. Additionally, $$\hbox {SiO}_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>SiO</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> </mml:math> surface morphology plays a significant role, with fully saturated interfaces showing lower energy and greater interlayer separations. In both $$\hbox {SiO}_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>SiO</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> </mml:math> / $$\hbox {MoS}_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>MoS</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> </mml:math> and $$\hbox {SiO}_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>SiO</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> </mml:math> / $$\hbox {WS}_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mtext>WS</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> </mml:math> systems, band gap predictions using PBE0 closely match the experimental values, underscoring the value of hybrid functionals for accurate electronic structure calculations. Graphic Abstract