First-principles computational analysis of the electronic and charge transport anisotropy of NbO<i>X</i>2 (<i>X</i> <b>=</b> Cl, Br, I) nanoribbons and nanosheets

The use of NbOX2 oxyhalide (X = Cl, Br, I) nanoribbons and nanosheets in next-generation nanoelectronic devices remains unfulfilled because the impact of the fundamental electronic properties of these materials on their practical device applications remains poorly understood. The present work applies first-principles density functional theory calculations to investigate the anisotropic electronic properties and quantum confinement effects of NbOX2 nanoribbons and nanosheets and their performance in field effect transistors. Our results reveal direction-dependent electron transport behaviors, with the most efficient transport occurring along the Nb-X axis. Quantum confinement in nanoribbons leads to bandgap widening, with Nb–O-oriented nanoribbons exhibiting more stable electronic properties. In addition, charge delocalization is confirmed along the Nb-X axis, and it strengthens with increasing halogen constituent mass.