Electronic and level statistics properties of Si/SiO2 quantum dots

Spherical shaped Si quantum dots (QDs) embedded into the SiO2 substrate are considered in the single sub-band effective mass approach. Electron and heavy hole sub-bands are taken into account. Non-parabolicity of the Si conduction band is described by the energy dependence of electron effective mass. Calculations of low-lying single electron and hole energy levels are performed. For small QDs (diameter D≤6 nm) there is a strong confinement regime when the number of energy levels is restricted to several levels. 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 with the model used in [2] (Moskalenko et al., 2007). For the 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 energy levels is calculated and results are discussed.