Substrate-induced structures of bismuth adsorption on graphene: a first principles study

• Published in: Physical chemistry chemical physics : PCCP Vol. 18; no. 28; pp. 18978 - 18984
• Main Authors: Lin, Shih-Yang, Chang, Shen-Lin, Chen, Hsin-Hsien, Su, Shu-Hsuan, Huang, Jung-Chun, Lin, Ming-Fa
• Format: Journal Article
• Language: English
• Published: England 28.07.2016
• Subjects: Adsorption; Arrays; Bismuth; Buffer layers; Graphene; Mathematical analysis; Monolayers; Substrates
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c6cp03406c

The geometric and electronic properties of Bi-adsorbed monolayer graphene, enriched by the strong effect of a substrate, are investigated by first-principles calculations. The six-layered substrate, corrugated buffer layer, and slightly deformed monolayer graphene are all simulated. Adatom arrangements are thoroughly studied by analyzing the ground-state energies, bismuth adsorption energies, and Bi-Bi interaction energies of different adatom heights, inter-adatom distance, adsorption sites, and hexagonal positions. A hexagonal array of Bi atoms is dominated by the interactions between the buffer layer and the monolayer graphene. An increase in temperature can overcome a ∼50 meV energy barrier and induce triangular and rectangular nanoclusters. The most stable and metastable structures agree with the scanning tunneling microscopy measurements. The density of states exhibits a finite value at the Fermi level, a dip at ∼−0.2 eV, and a peak at ∼−0.6 eV, as observed in the experimental measurements of the tunneling conductance. The geometric and electronic properties of Bi-adsorbed monolayer graphene, enriched by the strong effect of a substrate, are investigated by first-principles calculations.