Electronic structure of NaWO$_3$: Role of the impurity potential

TL;DR

This study uses ab-initio calculations to explore how Na doping affects the electronic structure of WO₃, revealing that the changes are primarily due to added electrons rather than impurity potential.

Contribution

It clarifies the role of impurity potential in Na-doped WO₃, showing that electronic structure modifications are mainly due to electron addition rather than impurity effects.

Findings

Electronic structure of NaWO₃ resembles that of added electrons in WO₃.

Impurity potential plays a minor role in electronic structure changes.

Rigid band approximation is valid over certain energy ranges.

Abstract

We have performed {\it ab-initio} electronic structure calculations to determine the evolution of the electronic structure of WO$_3$ with Na doping. Na doping introduces an additional electron when introduced into WO$_3$. The ensuing electronic structure of Na doped WO$_3$, we find, is very similar to the electronic structure of an electron introduced into WO$_3$, thus clarifying the role of the impurity potential due to Na. While the electronic structure of NaWO$_3$ allows a rigid band like description over a certain energy range, modifications introduced in the electronic structure can be related back to the electron due to Na and not the impurity potential that one generally believes to be responsible.