Size-dependent electronic decays and coherent phonon of CdSeTe quantum dots in glass matrix

The ultrafast decays of CdSexTe1−x (x=0.32) quantum dots in the glass matrix were reported by use of one-color pump probe experiments. The size varies from 7.8 to 22nm, has a longer rising time and a much longer lifetime. Obvious coherent phonons and electronic decays of CdSexTe1−x quantum dots (R=3.9nm) are found with the excitation of band-edge energy, but only long electronic decays of CdSexTe1−x quantum dots (R=5.3, 11.0nm) are observed. Coherent phonon is attributed to resonant excitation because of Fröhlich coupling. The component with long lifetime under non-resonant excitation originated from heat accumulation.