Controlled synthesis of compound semiconductor nanoparticles using microfluidic reactors

We describe the use of continuous-flow, microfluidic reactors for the controllable synthesis of compound semiconductor nanoparticles. Specifically, CdS nanoparticles are synthesised by rapid mixing of Na/sub 2/S and Cd(NO/sub 3/)/sub 2/.4H/sub 2/O flow streams within a silicon/glass micromixer based on the principle of flow lamination. Room temperature syntheses at a variety of volumetric flow rates yield CdS nanoparticles of variable polydispersity. Analysis of absorption spectra of the CdS nanoparticles suggests that varying volumetric flow rates of reagent streams provides a simple and direct method of controlling population dispersity. Simple, single layer glass microstructures are also used to synthesis CdSe nanoparticles in continuous flow at temperatures between 180 and 240/spl deg/C.