Size-dependent electronic energy relaxation in a semiconductor nanocrystal in the strong confinement limit

The size dependence of the electronic energy relaxation in a quantum dot is considered. The Förster energy transfer from an exciton in a quantum dot to a surface state of the dot is considered as a dominant channel of the electronic energy relaxation in a quantum dot. For the consideration of the relaxation mechanism, a microscopic quantum mechanical description of the exciton in the quantum dot and a macroscopic description of the surface state of the quantum dot are employed. From this analysis, it is shown that the relaxation rate increases as the radius R of the quantum dot decreases and the rate has 1/Rc dependence in the strong confinement regime, where c is considered to be a fraction between 3 and 4.