Controlled Synthesis of CdSe Quantum Dots by a Microwave-Enhanced Process: A Green Approach for Mass Production

A method that does not employ hot‐injection techniques has been developed for the size‐tunable synthesis of high‐quality CdSe quantum dots (QDs) with zinc blende structure. In this environmentally benign synthetic route, which uses less toxic precursors, solvents, and capping ligands, CdSe QDs that absorb visible light are obtained. The size of the as‐prepared CdSe QDs and thus their optical properties can be manipulated by changing the microwave reaction conditions. The QDs were characterized by XRD, TEM, UV/Vis, FTIR, time‐resolved fluorescence spectroscopy, and fluorescence spectrophotometry. In this approach, the reaction is conducted in open air and at a much lower temperature than in hot‐injection techniques. The use of microwaves in this process allows for a highly reproducible and effective synthesis protocol that is fully adaptable for mass production and can be easily employed to synthesize a variety of semiconductor QDs with the desired properties. Possible applications of the CdSe QDs were assessed by deposition on TiO2 films. Microwave quantum dots: The preparation of CdSe quantum dots (QDs) by a microwave (MW)‐enhanced process in aqueous solution is described. A selenium source (Na2SeSO3) was prepared by microwave heating of solution A at 100 W and 100 °C for 30 min. Then different sizes of CdSe QDs with different colors (red, orange, yellow) that can absorb in the visible region were prepared by microwave heating of solution B under different conditions.