INGAAS/GAAS Quantum Dot With Material Mixing
I. Filikhin, V.M. Suslov, B. Vlahovic
North Carolina Central University, US
InGaAs/GaAs quantum dots, Electron states, Single-electron tunneling
We model an InGaAs/GaAs quantum dot having dependence of the Ga fraction along vertical axis. The effect of material mixing on the electron energy spectra is considered. This theoretical model is based on a single sub-band approach and an energy dependence of the effective electron mass. An additional potential is included in the model to simulate the total effect of the strain, piezoelectricity and interband interactions. Based on our model we have performed analysis of the results obtained by direct treatment of strain effects (“ab initio” calculations). Also we compare the results obtained for energy spectra of few electrons, tunnelling into InAs/GaAs QD, with the capacitance-gate-voltage experimental data. This effective method is valid for the case of material mixing in the InGaAs/GaAs quantum dot. In the case of the linear height dependence of the Ga fraction the strength of effective potential has to be chosen as corresponding of an averaged value for the Ga distribution function. Effects of the QD cross section and the Ga fraction distribution are studied. We discuss obtained results with those of realistic model calculations.
Nanotech 2008 Conference Program Abstract