Electronic Properties of Exciton in Mg Based II–VI Wide Band Gap Semiconducting Quantum Dots

Electronic properties of exciton in Mg based ZnS, ZnSe and ZnTe wide band gap semiconductor cylindrical quantum dots are investigated taking into consideration of geometrical confinement effect. The confinement potentials for various concentrations of Mg alloy content in Zn_1–x Mg _x S/MgS, Zn_1–x Mg _x Se/MgSe and Zn_1–x Mg _x Te/MgTe quantum dots are studied and the constant barrier height is maintained for the Mg content in all the three heterostructures (Zn_0.9Mg_0.1S/MgS, Zn_0.25Mg_0.75Se/MgSe and Zn_0.09Mg_0.91Te/MgTe) to obtain the exciton binding energies and the optical transition energies. The results show that the band gap increases nonlinearly with the increase of composition of Mg alloy content in the taken materials due to the positive band gap bowing parameters and the exciton binding energies in Zn_0.9Mg_0.1S/MgS quantum dot are found to be more than the other two dots taken for studies. Our results will be helpful for some potential applications in full colour display devices and optical data storage devices.