Nano-Apertures for Single Quantum Dot Spectroscopy

EBL has been used to make sub-micron holes in an optically opaque metal mask on the surface of material containing self-assembled quantum dots. This enables spatially resolved photoluminescence (PL) and photocurrent spectroscopy to be selectively performed on only those dots that lie directly under the aperture. Provided the dot density is small, a single quantum dot can be studied in these structures. The figure below shows an SEM image of a typical aperture with a diameter of ~300nm.