Early time ripening during the growth of CdSe nanocrystals in liquid paraffin

The growth process of CdSe nanocrystals synthesized in paraffin hot-matrix is studied. The complex combination of nucleation, growth and ripening processes in the first stages of nanocrystal growth is known as early time ripening. It is found that the early time ripening depends on the synthesis temperature and the concentration of Se-precursor (tributhylphosphine selenide). Higher synthesis temperatures promote early time ripening thus leading to the formation of larger nanocrystals with lower concentration in the reaction solution. Increasing the Se-precursor concentration at 210 °C dramatically increases the nanocrystals concentration, but does not affect significantly their size. However, the larger amount of Se-precursor at 240 °C leads to larger nanocrystals size, although it has a little effect on the nanocrystal concentration.