Optical properties of type-I PbSe/CdSe core/shell quantum dot

Abstract

Electronic properties and optical properties of exciton in a PbSe/CdSe core/shell quantum dot are investigated taking into account the spatial confinement effect. The present model is based on the PbSe/CdSe quantum dot for type-I confinement regime. The dielectric mismatch effect and the self polarization potential are taken into consideration in the PbSe/CdSe quantum dot nanostructure. Polarization charges are incorporated at the interface of the core/shell materials. Numerical calculations on the electronic and optical properties are found with the ratio of radius of inner and outer shell materials for various shell radii. The exciton binding energy and the interband optical transition energies are computed using variational formulism within the single band effective mass approximation. The oscillator strength and the recombination life time are determined with the ratio of radius of core to shell materials taking into account the dielectric mismatch between the materials. The nonlinear absorption coefficients and the changes of refractive index are computed for the ground and first excited state using compact density matrix method. The obtained results are found to be in good agreement with those reported by other investigators.