Self-organized formation of unidirectional and quasi-one-dimensional metallic Tb silicide nanowires on Si(110)

Terbium induced nanostructures on Si(110) and their growth are thoroughly characterized by low energy elec-tron diffraction, scanning tunneling microscopy and spectroscopy, core-level and valence band photoelectron spectroscopy, and angle-resolved photoelectron spectroscopy. For low Tb coverage, a wetting layer forms with its surface fraction continuously decreasing with increasing Tb coverage in favor of the formation of unidirectional Tb silicide nanowires. These nanowires show high aspect ratios for high annealing temperatures or on substrates already containing Tb in the bulk. Both wetting layer and nanowires are stable for temperatures up to 750 degrees C. In contrast to the nanowires, the wetting layer is characterized by a band gap. Thus, the metallic nanowires, which show a quasi-one-dimensional electronic band structure, are embedded in a semiconducting surrounding of wetting layer and substrate, insulating the nanowires from each other.

Automated summary

The terbium-induced nanostructures and their growth on Si(110) were comprehensively characterized using various techniques. It was found that a wetting layer formed at low terbium coverage, which gradually decreased with increasing coverage to give rise to unidirectional terbium silicide nanowires. These nanowires exhibited high aspect ratios at high annealing temperatures or on substrates containing terbium. The wetting layer and nanowires were both stable at temperatures up to 750 degrees C. In contrast to the nanowires, the wetting layer had a band gap, resulting in the semiconducting surrounding that insulated the nanowires.