Feature-rich electronic properties of aluminum-doped graphenes

TL;DR

This study uses first-principles calculations to explore how aluminum doping alters the electronic properties of graphene, revealing rich features like energy band shifts, free electron behavior, and the impact of different adatoms on structure and electronic states.

Contribution

It provides a detailed analysis of aluminum-doped graphene's electronic structure, highlighting the effects of multi-orbital hybridizations and comparing with other dopants like alkali and halogen.

Findings

Al-doped graphene shows quasi-rigid energy band shifts.

High free carrier densities are induced by Al and alkali dopants.

Differences in electronic structures depend on orbital hybridizations and adatom types.

Abstract

The electronic properties of aluminum-doped graphenes enriched by multi-orbital hybridizations are investigated using first-principles calculations. The feature-rich electronic structures exhibit the quasi-rigid red shifts of the carbon-created energy bands, the Al-dominated valence and conduction bands, and many free electrons in the conduction Dirac cone. These are directly reflected in the special structures of density of states (DOS). The Al- and alkali-induced high free carrier densities are almost the same. There exist certain important differences among the Al-, alkali- and halogen-doped grapehenes, such as, the buckled or planar graphene, the preserved or seriously distorted Dirac cone, the existence of the adatom-dominated valence bands, the free electrons or holes, the degenerate or splitting spin-related states, and the simple or complicated peaks in DOS. The similarities and differences mainly come from the diverse orbital hybridizations in adatom-C bonds, as indicated from the atom-dominated bands, the spatial charge distributions and the orbital-projected DOS.