Hole storage in GaSb/GaAs quantum dots for memory devices

Abstract

Abstract The hole confinement of self‐organized GaSb/GaAs quantum dots embedded in n + p‐diodes is investigated experimentally by admittance spectroscopy. The highest thermal activation energy obtained, 400 meV, refers to only weakly charged quantum dots. Detailed bias‐dependent investigations allow to study state‐ filling and Coulomb charging effects. State filling lowers the activation energy down to 150 meV in quantum dots charged with the maximum number of about 15 holes. The observed thermal activation barrier for GaSb/GaAs quantum dots is about twice as high as for structurally comparable InAs/GaAs quantum dots.