Insights into the interfaces of VO2(M) and VO2(B) polymorphs with different substrates

The phenomena arising at the interface between oxide materials and substrates can fundamentally and practically change the physical and chemical properties of the materials themselves. In this study, we employed density functional theory (DFT) calculations to elucidate the stability and optical properties of VO2(M) and VO2(B) interactions with substrates of sapphire(c-cut), sapphire(r-cut), SrTiO3(001), SrTiO3(111), SrNbO3(001), SrNbO3(111), LaAlO3(c-cut), and LaAlO3(r-cut). The surface calculations showed that the fully relaxed SrTiO3(111) and SrNbO3(001) possess the highest energies of 31.8 eV nm−2 and 21.15 eV nm−2 relative to other slabs, before optimizing with VO2(M) and VO2(B) polymorphs, respectively. The calculated adsorption energy indicated that the interface of VO2(M) and VO2(B) structures showed more stability on SrTiO3(001) and SrTiO3(111), with adsorption energy values of 2.83 eV and 0.91 eV, respectively. Furthermore, the optical absorption properties of the highest and lowest stable interfaces have been evaluated. The outcomes predicted that VO2(M)@SrTiO3(001) and VO2(B)@SrTiO3(111) have their optical adsorption in the visible light range, while VO2(M)@sapphire(c-cut) and VO2(B)@sapphire(c-cut) showed the main adsorption peak in the infrared region.