Optimization of the optical properties of nanostructures through fast numerical approaches

We present an improved and efficient numerical method to determine the optical properties of nanostructures starting from the electronic properties. We study the variation of electronic and optical properties induced by confinement effects in semiconductors quantum objects. We solve the time-independent Schrodinger equation with a new formulation of a shooting method under the effective mass approximation. This formulation is adapted to quantum wells, circular cross-section quantum wires and spherical quantum dots. We applied a correction on the mass to take into account the nonparabolicity of the band structure. The correction gives an accuracy comparable to more demanding calculation methods such as 8-bands k.p, tight binding or even semi-empirical pseudopotential methods. Our results remain valid even for low-bandgap materials and sizes as small as 1 nm. The calculation speed of our method allows optimization procedures that give better understanding of experimental results concerning CdS, CdSe, PbS and PbSe spherical quantum dots. We consider extensive data from the literature. We focus on the relations between the electronic structure and absorption and photoluminescence spectra measured on spin-coated PMMA thin-films containing (core)shell nanoparticles.