On the prospects of layeredness in tantalum pentoxide

Highlights: • Ta₂O₅ is stabilized in layers. • The bulk and monolayer are direct band gap semiconductors. • The material with increase in number of layers exhibited metallic nature. • Exfoliation energy is 30 meV/atom. • The conduction band and valance band are of Ta-d and O-p states respectively. First principles calculations were carried out at different levels of theory to study the structural and electronic properties of Ta₂O₅ in bulk and slab periodicities. The material behaves as 2D layered material in slab periodicities with the average intra-layer TaO bond length 1.7 –1.9 Å and average interlayer distance 2.35 Å. The investigations also involved periodic energy decomposition analysis (pEDA), potential energy surface (PES) and phonon structure calculations. The electronic properties reveals that conduction band of the material comprises of Ta-d whereas the valence band is of O-p states. The bulk and monolayer are direct band gap semiconductors having respective values of band gap as 0.20 eV and 1.6 eV whereas the material with increase in number of layers exhibited metallic nature due to Ta-d states at Fermi level. The material stabilized as layered with calculated value of exfoliation energy as 30 meV/atom.