Optical absorption, induced bleaching, and photoluminescence of CdSe nanoplatelets grown in cadmium octanoate matrix
1 Institute of Physics of National Academy of Sciences of Ukraine, Nauky prosp., 46, Kyiv 03028, Ukraine
2 Faculty of Physics, Taras Shevchenko National University of Kyiv, Academician Glushkov prosp., 2, Kyiv 03022, Ukraine
3 V. I. Vernadsky Institute of General and Inorganic Chemistry of National Academy of Sciences of Ukraine, Academician Paladin prosp., 32-34, Kyiv 03142, Ukraine
Nanoscale Research Letters 2014, 9:88 doi:10.1186/1556-276X-9-88Published: 20 February 2014
CdSe nanoparticles (NPs) are chemically synthesized in thermotropic ionic liquid crystalline (LC) phase of cadmium octanoate that was used as a nanoreactor. The nanocomposite samples are obtained by the rapid cooling of the LC phase to room temperature. Observed doublet structure in absorption spectra of the nanocomposites is characteristic for the two-dimensional CdSe nanoplatelets (NPLs). The thicknesses of the CdSe NPLs are 1.6, 1.9 and 2.3 nm as determined from the absorption spectra, and correspond to 4, 5 and 6 CdSe monolayers, respectively. Induced simultaneous bleaching of the doublet components observed under femtosecond laser excitation, as well as photoluminescence spectra and their kinetics are found compatible with the model of excitons with heavy- and light-hole valence bands confined in nanoplatelets.