Magneto-optical study of quantum confinement in Cd(S,Se) quantum dots

A well-distinguished excitonic structure of the absorption spectrum of Cd(S,Se) quantum dots (QD) was obtained using magnetic-circular-dichroism measurements. This method enabled us to observe at least four distinct excitonic absorption peaks, which were successfully assigned to heavy-hole and light-hole exciton levels. The assignment was made for the QD with infinite confining barrier, but taking into account electrostatic electron-hole interaction as well as their interactions with the charge polarized at the surface of the QD. The effective radius of the QD estimated from the theoretical calculation was confirmed by the transmission-electron microscopy.