Self-Assembly of Ordered Semiconductor Nanoholes by Ion Beam Sputtering

Periodic nanohole arrays are formed on a Ge substrate by self-assembly using focused ion beam sputtering at normal incidence with an energy of 5 keV. The figure shows an SEM image of a hexagonally ordered hole domain that has hexagonally ordered quantum dots-20 nm diameter and 3 nm height-around each hole The structured Ge has high surface area and a considerably blue-shifted energy gap.