The epilayer of vertically stacked

self-assembled InAs Quantum Dots (QDs) was grown by MBE with solid sources in non-cracking K-cells

and the sample was fabricated to a FET structure using a conventional technology. A quantum dot (QD)

the behavior of which is to capture and emit carriers like a giant trap

is studied using deep level transient spectroscopy (DLTS) technique. The electrons and holes in the QDs are respectively emitted from the relevant energy levels to the conduction and valence bands of the barrier layer with increasing measurement temperature

and the thermal emission energies from the QDs are related to their discrete energy levels. The 5-period vertically stacked InAs QDs in the barrier layer of a field-effect type structure were measured

and the results were found to correspond to the capacitance-voltage and photoluminescence properties. At 77K and room temperature

the threshold voltage shift values are 0.75V and 0.35V

which are caused by the trapping and detrapping of electrons in the quantum dots. Discharging and charging curves form a part of a hysteresis loop exhibiting a memory function. The electrical injection of confined electrons in QDs products the threshold voltage shift and memory function with the persistent electron trapping

which shows the potential use for a room temperature application.