Electronic Structure And Its Dynamical Properties Of Semiconductor Quantum Dot Molecules

In this thesis, we have made a deep investigation on two subjects which are related to the experiment and theory of quantum dot molecule. The one is about the electronic energy spectra and the optical properties of the self-assembled quantum dot in-a-well structure (DWELL). The other is about the dynamical behaviors of the charge particles in quantum dot molecule driven by an AC electric field. These dynamical behaviors are caused by the electron-electron interaction, electron-hole interaction, and spin interaction. By carrying out the theoretical analysis, some new quantum effects are predicted.In Chapter 2, the effective mass approximation and adiabatic approximation are applied to calculate the electronic energy spectra of the InAs/In_xGa_1-xAs DWELL under various structural parameter. It turns out that the energy spectra is sensitive to the structural parameter variation of quantum dot (QD) and quantum well (QW). The computations suggest that the QD with smaller size and higher confining potential have a higher electron and hole energy levels which result in the PL peak wavelength a small blue shift, and the narrower QW and thinner self-assembled QD wetting layer (WL) have similar conclusions. The photoluminescence (PL) spectra is calculated as well. Using the same method, we also calculate the electronic energy spectra of the GaN/Ga_xAl_1-xN DWELL. The results are consistent with the previous calculation. We think that the calculations are useful to the design of quantum dot laser.Using the Hubbard model and the Floquet theorem, we study the dynamical behaviors of an exciton confined in a two coupled quantum dots driven by an AC electric field in Chapter 3. Although the directions of Coulomb interaction force and the directions of electric field force in the exciton system are different from that in the two-electron system, both effects of these two forces are opposite in these two systems. Moreover, in two quantum dot system the electron tunnelling and the hole tunnelling are different. Nevertheless, the calculations indicate that the initial...