Optical peak gain in a PbSe/CdSe core-shell quantum dot in the presence of magnetic field for mid-infrared laser applications

Magnetic field induced electronic properties and some nonlinear optical properties of an exciton are investigated taking into account the geometrical confinement effects in a PbSe/CdSe core-shell heterostructure. The effects of dielectric mismatch between the inner and outer materials, built-in internal electric fields and the self-polarization potential are included in the calculation of obtaining these properties. Self-polarization charges are incorporated at the interface of the core-shell materials. The magnetic field dependent exciton binding energies are found with the ratio of core-shell radii of the dot using variational formulism within the single band effective mass approximation. The magnetic field induced oscillator strength and the radiative life time of the exciton are studied for a constant dot radius. The absorption coefficients and the optical gain as a function of photon energy, the peak gain with the current density are investigated in the PbSe/CdSe core-shell dot for various values of magnetic field strength.