Intersubband optical transition energy in a CdTe/Zn0.2Cd0.8Te/ZnTe core/shell/shell spherical quantum dot with Smorodinsky–Winternitz confinement potential

Abstract

Electronic and optical properties of a hydrogenic donor impurity in a CdTe/Zn0.2Cd0.8Te/ZnTe core/shell/shell quantum dot are discussed taking into consideration of geometrical confinement effect. The confining potentials on both the sides of the barrier are different and a two parametrical potential of Smorodinsky–Winternitz is considered in this problem. The dielectric mismatch is included in the Hamiltonian. The position dependent effective mass is applied. The electronic properties are studied using variational method and the optical properties are investigated using the density matrix approach. The intersubband optical absorption, the oscillator strength and the radiative life time between ground and the excited states are studied based on the wave functions and the confined energies with and without the impurity with various dot radii. The results show that the absorption wavelength in type-II core and shell semiconducting nanomaterials can be tuned over a wider range of wavelengths by altering their size and the composition.