In the present work we develop a theoretical study to analyze how the image charges effects can modify the electronic properties in Si and SrTiO3-based quantum wells. We have used the method based on the calculation of the image charge potential by solving Poisson equation in cylindrical coordinates. The numerical results show that the electron-heavy hole recombination energy can be shifted by more than 200 meV due to the combination of charge image and SiO2 (SrTiO3) interface thickness effects.

The energy spectrum and optical absorption of confined carriers in ellipsoidal CdSe quantum dots are calculated. Our model relies on the effective mass approximation and Fermi's golden rule for the electronic structure and optical properties, respectively. We demonstrate that the electronic structure and the interband optical absorption are highly dependent on the ellipsoid aspect ratio.

We report a detailed analysis of how the existence of interface roughness can change exciton localization in CdTe/Cd1-xMn xTe strained double quantum wells (DQW´s) taking into account magnetic and electric field effects. We consider that the potential, effective mass, and the intrinsic magnetization are dependent on the profile of the Mn molar fraction at the interfacial region. Results obtained with CdTe/Cd0.68Mn0.32Te DQW´s show that the energy band tailoring generated by the strain and the Zeeman effect is responsible by a displacement of the exciton energy peaks and that small changes in the interface width (10 Å) can be responsible for 30 meV exciton energy broadening.

We investigate the confined exciton properties in InGaN/GaN cylindrical quantum wires. We have solved numerically Schrödinger-like equations in the effective mass approximation and have found the energy levels and wavefunctions for confined electrons and holes, using these results to calculate variationally the confined exciton energy. A comparison was made between graded and abrupt quantum wires, showing that the existence of smooth interfaces enhances the confined exciton energy if the wire radius is smaller than 50 Å. We conclude that the existence of graded interfaces must be considered for a better description of the exciton based optical properties of InGaN/GaN quantum wires.

In order to analyze the charging effects on electronic spectrum of Silicon (Si) based quantum wells (QW's), we use a method based on the calculation of the image charge potential by solving Poisson equation in cylindrical coordinates. The numerical results shows that the confined electron ground state energy level can be shifted by more than 50 meV due to the contribution of the image charges to the confinement potential of the graded quantum well.

This work reports the influence of a dc external magnetic field on the polaritons propagating in cylindrical systems. We present numerical results for the dispersion relation and energy flow for surface polaritons modes propagating in hollow and massive cylinders made of GaAs and InSb.

We perform a theoretical investigation of the absorption and emission properties of quantum confined SiC/SiO2 spherical quantum dots, focusing on the the size-dependent emission and absorption spectra of an independent single dot. We observed strong oscillations in the absorption lines as a consequence of the interband transitions rules, and a blue-shift of the emission spectra lines with the decrease of the quantum dot diameter.

We investigate the con.nement properties of GaN/Al xGa1-xN zincblende and wurtzite nonabrupt quantum wells (QWs) in an electric field. It is shown that their Stark shifts decrease considerably when the existence of nonabrupt interfaces are considered. Confined excitons in 50 Å wide GaN/Al0.3Ga0.7N zincblende and wurtzite quantum wells (QWs) can exist up to electric field intensities of the order of 500 kV/cm. In all cases, the electric field effects in GaN/Al xGa1-xN wurtzite QWs are stronger than in similar zincblende QWs.

It is shown that the existence of nonabrupt interfaces modify electric field effects on the electron transmission through a GaAs/AlxGa1-xAs double-barrier. When the applied electric intensity is 25 kV/cm, and the abrupt well and barriers are 100 Å wide, interfaces as thin as two GaAs lattice parameters are responsible for shifts at least of 10 meV in the electron tunneling resonance energies. The type of interface potential and electron effective mass description changes significantly theoretical results related to the electric field influence on the electron transmission properties.