عنوان مقاله [English]
CdSe (Core) and CdSe/ZnS (Core/Shell) nanocrystals were produced using a green synthesis method by using phosphine- free precursor materials. The optical properties of the produced nanocrystals were investigated using UV- Vis absorption and PL emission spectra, and the average size of the nanocrystals was estimated optically using the absorption data. Size and morphology of the nanocrystals were also investigated using Williamson- Hall analysis and the TEM images. Our results show good agreement among the mentioned three different methods. Thus, size of CdSe nanocrystals was estimated within the 5.5-8.5 nm range. It was shown by X-ray diffraction method that CdSe nanocrystals, with zinc-blende structure, are formed. With increasing the growth time and decreasing the temperature, a red-shift was observed in both absorption and emission edges, which indicates an increase in the size of the grown nanocrystals. After core/shelling the nanocrystals, red-shifts of ~ 10 nm and ~ 30-40 nm were observed in the absorption and emission spectra of the grown nanocrystals, respectively. Accordingly, in our method it was possible to obtain CdSe nanocrystals, with justified green emission, without using octadecene.