Facile synthesis of CdSe quantum dots in a high-boiling two-phase liquid/liquid system

Abstract

We introduce a facile way to synthesize high-quality CdSe quantum dots (QDs) in a high-boiling two-phase liquid/liquid system. The cadmium myristic acid salt (Cd-MA) dispersed in the dimethylbenzene and selenourea dissolved in the ethylene glycol (EG) reacted at the two-phase interface for the nucleation and growth of nanocrystals. The n-trioctylphosphine oxide (TOPO) was used as capping agent of the CdSe QDs. In this route, the selenourea used as the precursor was dissolved in viscous ethylene glycol (EG), which facilitated the control of the nanocrystal growth by virtue of the slow decomposition and diffusion of selenourea in EG. The size, shape, crystalline structure and optical properties of CdSe QDs were investigated by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), UV⿿vis spectrometer and photoluminescence spectroscopy. This route could be exploited to synthesize nanocrystals with a large scale and could broaden to synthesis of metal or other semiconductor nanocrystals.