540-meV Hole Activation Energy for GaSb/GaAs Quantum Dot Memory Structure Using AlGaAs Barrier

We report on a memory structure that only makes use of holes as the storage charges based on type-II GaSb/GaAs quantum dots (QDs) using an AlGaAs barrier. The
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measurements confirm existence of quantum states in the GaSb dots and reveal the applied bias voltage range for the write/erase process by charging/discharging the QDs. A large hole activation energy value of 540 meV is obtained for the device measured by deep level transient spectroscopy. Our results indicate that type-II GaSb/GaAs QD system is a promising candidate for future memory devices.