We created a two-dimensional array of sub-10 nm Si-nanodiscs (Si-NDs), i.e. a 2D array of Si-NDs, with a highly ordered arrangement and dense NDs by using a new top-down technique comprising advanced damage-free neutral-beam (NB) etching and a bio-template (iron oxide core) as a uniform sub-10 nm etching mask. The bandgap energy (Eg) of the fabricated 2D array of Si-NDs can be simply controlled from 2.2 to 1.3 eV by changing the ND thickness from 2 to 12 nm. Due to weak quantum confinement existing in the diameter direction resulting from the sub-10 nm Si-ND diameter, even though the thickness of the Si-ND is much larger than the Bohr radius of Si, Eg is still larger than the 1.1 eV Eg of bulk Si. Si-ND not only has wide controllable Eg but also a high absorption coefficient due to quantum confinement in three dimensions. This new technique is a promising candidate for developing new nanostructures and could be integrated into the fabrication of nanoelectronic devices.
ASJC Scopus subject areas
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering
- Electrical and Electronic Engineering