Spherical shaped Si quantum dots (QDs) embedded into the SiO2 substrate are considered in the single sub-band effective mass approach. The electron and heavy hole sub-bands are taken into account. The energy dependence of electron effective mass is applied especially for small size QD. Calculations of low-lying single electron and hole energy levels are performed.
For QD of small sizes (diameter D≤6 nm) there is a strong confinement regime when the number of energy levels is restricted to several levels. The first order of the perturbation theory is used to calculate neutral exciton recombination energy taking into account the Coulomb force between electron and heavy hole. The PL exciton data are reproduced well by our model calculations. We also compare the results with those obtained within model .
For weak confinement regime (size D≥10 nm), when the number of confinement levels is limited by several hundred, we considered the statistical properties of the electron confinement. Distribution function for the electron levels is calculated and results are discussed.