Abstract
We report on the excitation spectra of the coherent emission from nanoseconds laser-induced population-grating (CPG) in the fundamental absorption edge of CdS 0.3 Se 0.7 quantum dots with the dot size of the order of 10 v nm. We have observed successfully that two dominant spectral peaks appear in the CPG excitation spectra around the blue shifted absorption edge. This result suggests that the binding energy of the lowest energy exciton, so called A-exciton, in the quantum dots would be of the order of 70 v meV. The probe frequency dependences of the CPG excitation spectra allow us to discuss the excitation energy dissipation effect and the influence of the discrete joint density of states in the quantum confinement system on the CPG excitation spectra.
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