Investigation of the electronic structure of biphenylene ribbons of the armchair type

TL;DR

This study analyzes the electronic properties of biphenylene ribbons of various widths using the Hubbard model, revealing their transition from semiconductor to metal as width increases, with implications for nanoscale electronic applications.

Contribution

It provides a theoretical framework for understanding the electronic spectrum of biphenylene ribbons and predicts their conductive transition based on width, supported by comparison with experimental data.

Findings

Ribbons with 6-18 carbons are semiconductors.

Band gap decreases exponentially with width.

Ribbons with 21+ carbons are metallic.

Abstract

The electronic structure of chair-type biphenylene ribbons is studied within the framework of the Hubbard Hamiltonian in the approximation of static fluctuations. An expression is obtained for the Fourier transform of the Green's functions, whose poles determine the spectrum of elementary excitations. The energy spectrum of biphenylene ribbons indicates that nanoribbons with a width of 6, 9, 12, 15, 18 carbon atoms are in the semiconductor state. Densities of state of electrons of biphenylene ribbons of various widths are presented in comparison with the results of experimental measurements of differential conductance of biphenylene ribbons. It is shown that the width of the band gap decreases exponentially with an increase in the width of the biphenylene ribbon. Ribbons with a width of 21 carbon atoms or more are in the metallic state.