Fabrication of Ge quantum rings from droplets by pulsed laser deposition

Abstract

Two-dimensional Ge quantum single rings and polyrings were prepared on a Si(100) matrix by using the droplet technique in pulsed laser deposition. The complete rings with well-defined sharp inner and outer edges were formed via an elastic self-transforming process of droplets into nanorings in the presence of Ar gas. The single rings were from the separated droplets while the polyrings were from a few partially overlapped droplets. The self-transformation is likely to be driven by the strain of Ge/Si layers and the surface tension. The planar quantum rings of Ge formed by the deformation of droplets may be useful for investigating growth processes, fundamental physics phenomena, and nanoscale devices.