Optical absorption coefficients in a CdSe/Pb1−xCdxSe/CdSe spherical quantum dot quantum well nanostructure

•Some optical properties are discussed in a spherical quantum dot-quantum well nanostructure.•The core and shell are taken as the same material.•The variation of optical transition energy with the dot radius of well-dot is brought out.•Oscillator strength as a function of photon energy is investigated with the dielectric mismatch.

Exciton binding energies, optical transition energies and the absorption coefficients are investigated taking into consideration geometrical confinement, dielectric mismatch and the self-polarization potential in a CdSe/Pb1−xCdxSe/CdSe spherical quantum dot-quantum well nanostructure. The core and shell are taken as the same material. The exciton binding energy and the interband emission energy have been found using a variational method within the single band effective mass approximation. The binding energies of the exciton as a function of dot radius of the well dot with the different dot radii and the dielectric constants of the core and shell materials are studied. The variation of optical transition energy with the dot radius of well-dot is brought out. The oscillator strength and the radiative transition lifetime as a function of photon energy are investigated with the dielectric mismatch.

Graphical abstractVariation of oscillator strength as a function of well-dot radius in a CdSe/Pb1-xCdxSe/CdSe quantum dot quantum well nanostructure for various Cd alloy content in the core and shell materials is shown in the figure. It is shown that the oscillator strength is more influenced by the dielectric mismatch.Figure optionsDownload full-size imageDownload as PowerPoint slide