Controlled Synthesis of CdSe Quantum Dot by Non―coordinating Solvent Approach in a Micro―flow―reactor

Adopting the micro―reactor technology, CdSe quantum dots were controlled synthesized in a low toxicity system of octadecene (ODE) and oleic acid (OA) as the non―coordination solvent and the ligand, respectively. The effect of reaction conditions on particle size and the particle number of prepared CdSe quantum dots were studied in detail. The results indicated that reaction temperature has little effect on the particle number, however, appropriate high temperature favored a tight size distribution with enhanced florescence intensity. Under constant conditions, excessive Se was beneficial to generate a large number of small particles. With n(Cd):n(Se) = 1:5, the yield of CdSe quantum dots is close to 100%. The ligands quantity in the reactants directly affects concentration of the monomer. By controlling the concentration of the ligand OA and reaction time, a series CdSe quantum dots are successfully prepared displaying from blue to red fluorescence with particle size of 2.2―4.3nm.