Germanium nano disk array fabrication by combination of bio template and neutral beam etching for solar cell application

A high density uniform 10 nm amorphous Ge nanodisk structure could be successfully fabricated by a combination of a bio-template to fabricate a high density etching mask of 7 × 10 11 cm −2 and a neutral beam top-down process. Center-to-center distance of each ferritin was estimated at 13 nm. The fabricated Ge nanostructure showed increasing band gap energy from 1.5 eV up to 1.9 eV when the thickness of the nanostructure was decreased from 8 nm to 2 nm. The fabricated high density germanium nanostructure is expected to be used in many quantum effect devices such as quantum dot solar cells.