10(6) years extrapolated hole storage time in GaSb/AlAs quantum dots

Abstract

A thermal activation energy of 710 meV for hole emission from InAs/GaAs quantum dots (QDs) across an Al(0.9)Ga(0.1)As barrier is determined by using time-resolved capacitance spectroscopy. A hole storage time of 1.6 s at room temperature is directly measured, being three orders of magnitude longer than a typical dynamic random access memory (DRAM) refresh time. The dependence of the hole storage time in different III-V QDs on their localization energy is determined and the localization energies in GaSb-based QDs are calculated using eight-band k center dot p theory. A storage time of about 106 years in GaSb/AlAs QDs is extrapolated, sufficient for a QD-based nonvolatile (flash) memory. (c) 2007 American Institute of Physics.