Synthesis and spectroscopic study of high quality alloy Cd_xZn_1-xS nanocrystals

Abstract

In the present study, we report the synthesis of high quality Cd_xZn_1-xS nanocrystals alloy at 150°C with changing the composition. The shifting of absorption and emission peak in shorter wavelength is obtained with increasing the mole fraction of zinc. The quantum yield (QY) value decreases with increasing the Cd mole fraction and the values are 0.08, 0.13 and 0.40 for Cd_0.62Zn_0.38S, Cd_0.52Zn_0.48S and Cd_0.31Zn_0.69S nanocrystals, respectively after 120 min of reaction. However, the full width at halfmaximum (fwhm) values are 45, 34 and 28 nm and the corresponding quantum yield (QY) values are 0.52, 0.17 and 0.13 for 0.5 mM, 1.5 mM and 3 mM of initial S concentrations, respectively. It is interesting to note that the radiative decay time is dominating with increasing the Cd content. Analysis suggests that the decay dynamics depends on the composition of Cd_xZn_1-xS nanocrystals.