title: Controlling the fluorescent properties of aqueous CdTe nanocrystals by modulating the growth rate.
abstract: Although high quality aqueous CdTe and CdTeS alloyed quantum dots (QDs) have been synthesized in recent years, the relationship between the fluorescent properties and the growth kinetics has not been well documented yet. In this paper, 3-mercaptopropionic acid stabilized aqueous CdTe nanocrystals (NCs) are generally prepared with an improvement of the "traditional" synthetic approach, where the preparation of the red emission NCs is usually time-consuming due to the slow growth rate. The investigation on the kinetic and thermodynamic growth process shows that the growth can be effectively accelerated by decreasing the ligand concentration from 0.06 to 0.01 mol/L or elevating the growth temperature from 120 to 240 degrees C. In contrast to previous results, the quantum yield (QY) of the CdTe NCs is heightened to 45% only by increasing properly the growth rate. Our experiments depict that high growth rate favours high concentration of free monomers and thus decreases the number of the surface Te atoms of the NCs, leading to the enhancement of the photoluminescence (PL) QY.
authors: State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Eastern South Lake Road, Changchun 130033, China.
authors: Qinghui
authors: Q
authors: Zeng
authors: Youlin
authors: Y
authors: Zhang
authors: Bin
authors: B
authors: Xue
authors: Kai
authors: K
authors: Liu
authors: Limin
authors: L
authors: An
authors: Langping
authors: L
authors: Tu
authors: Xiaomin
authors: X
authors: Liu
authors: Xianggui
authors: X
authors: Kong