Temperature and frequency dependent admittance of InAs self-assembled quantum dots embedded in GaAs

We have studied using frequency and temperature dependent admittance some electronic properties of InAs QDs embedded in a GaAs structure. The presence of QDs in our structure is evidenced in the C-V characteristics at all temperatures and frequencies by a plateau-like structure that is related to charging and discharging of QDs. Concurrently, the conductance shows a manifest peak in a certain bias range for temperatures below 150K. The conductance dependence on both temperature and applied bias reveal two different mechanisms of carrier escape from the QDs. Moreover, the conductance data at a given frequency was used to estimate rates and activation energies in association with the electron escape mechanisms from the QDs.