Modeling of ZnTe Quantum Dots (QDs) embedded in a ZnMnSe matrix

The redshift of the Photoluminescence (PL) peak from ZnTe Quantum Dots embedded in a ZnMnSe matrix in an external magnetic field is dependent on the wavelength of the photon energy of the exciting laser. When the laser wavelength is 488 nm (the photon energy below the matrix gap but above the ZnTe QDs) we find a significantly higher red shift in the PL than the shift when a laser with a wavelength of 405 nm (the photon energy is above the ZnMnSe matrix) is used. The redshift in the PL is enhanced further with increasing Mn concentration in the matrix. Our theoretical studies show that 488 nm excitation results in hole wave functions which extends more into the ZnMnSe matrix compared to excitation with 405 nm. Using the linear variational method, we numerically diagonalize the QD Hamiltonian and find that 488 nm excitation results in a QD occupied with two holes whose delocalization from the QD center increases with increasing Mn concentration.