Influence of synthesis temperature on linear and nonlinear optical properties of water soluble luminescent Cd1-xZnxTe nanocrystals

Abstract

In This paper Cd1-xZnxTe nanocrystals were synthesized in aqueous phase, in presence of TGA as stabilizer. The samples have been characterized by X-ray diffraction (XRD) which confirmed that the alloyed nanocrystals were formed and crystal structure is FCC. The synthesis temperature effect on linear optical properties of the nanocrystals has been studied by UV-Vis absorption and Photoluminescence (PL) spectroscopy. It can be observed a red shift in emission and absorption peaks by increasing the synthesis temperature. All obtained samples display a narrow PL and sharp absorption spectra. Nonlinear indices of Cd1-xZnxTe nanocrystals were defined by the Z-scan technique using CW He-Ne laser (λ=632.8nm). The results reveal that these nanoparticles exhibit strong NLO effect such as self-defocusing and two photon absorption. The Z-scan results show that by increasing the synthesis temperature, the nonlinear coefficients were reduced.