Scanning tunneling microscope study of capped quantum dots

On thinly capped InGaAs/GaAs quantum dots (QDs), a simultaneous study of both the microscopic and electronic structures was carried out using scanning tunneling microscopy (STM). Although the surface is morphologically flat, the STM image of the embedded QDs can be clearly observed at cryogenic temperatures and is distinguishable up to room temperature. Such images are available in a particular bias range, which corresponds to the occurrence of QD-associated current, as demonstrated in scanning tunneling spectroscopy. (C) 2004 American Institute of Physics.