Electronic Band Structure of Bulk and Monolayer V2O5

Vanadium oxide (V2O5) is a material that can be fabricated as a thin film of only a few atomic layers thick during mechanical exfoliation due to the weak interlayer interactions, much like how graphene is created. During this project we looked at the band structure of both the bulk and mono-layered V2O5. We used computer software called ABINIT, which is installed on the high performance computer cluster (HPCC), to do all of our calculations. We used the projector augmented wave (PAW) method in our band structure calculations. The construction of the PAW potentials for vanadium was studied during our project and we found that the 3s and 3p bands of vanadium needed to be treated as valence bands in order to avoid ghost bands from appearing in our calculations. We tested the convergence of the plane wave energy cut-off parameter and its accuracy first with metallic body centered cubic (BCC) vanadium and then with rock salt structured vanadium monoxide (VO). The band structure of V2O5 can be characterized as oxygen 2s and 2p like bands separated by a gap from the vanadium 3d like conduction bands. The band gap between them is indirect. There are two narrow bands that fall just below the conduction band called intermediate bands. Many interesting properties can arise from these intermediate bands such as transport phenomena or mediating optical transitions from the valence bands to higher conduction bands.