Self-organized Ge quantum wires on Si(111) substrates

Self-organized Ge quantum wires have been grown on regular atomic steps formed along [1̄10] direction on Si(111) substrates by annealing at 870 °C in vacuum. The samples have been studied by ex situ atomic force microscopy (AFM), Raman scattering and low temperature photoluminescence spectroscopy. The AFM results suggest that the mechanism of the formation of the wires be the evolution of self-organized lined-up quantum dots. Good quality Ge quantum wires have been formed and clear quantum confinement-induced quantization in the wires has been observed.