Electronic Structure of Bi Nanoribbon: Greatly Influenced by Edge Chirality and Edge Reconstruction

Structural, energetic, and electronic properties of one-dimensional armchair and zigzag Bi nanoribbons (A and ZBNRs) are systematically investigated within the framework of density functional theory. The presence of edge reconstruction greatly enhances the structural stability of both A- and ZBNIts. ABNRs are indirect band gap semiconductors and their indirect band gaps exhibit width-dependent odd-even oscillation, while the direct band gaps at the Gamma point monotonically decrease with increasing the ribbon width clue to quantum confinement effect. The Peierls transition in the ZBNRs turns the ZBNIZs from metals into semiconductors accompanying dimerized Bi atoms at both edges and stabilizing the ribbons.