One-pot synthesis of high quality CdS nanocrystals by microwave irradiation in an organic phase: a green route for mass production

High quality CdS nanocrystals emitting from 412 to 458 nm were synthesized by a simple one-pot noninjection microwave irradiation route using low-cost, air-stable CdO, S powder, 1-octadecene and oleic acid as the starting materials under air atmosphere. With simple variation of the reaction recipe (growth temperature and time), the absorption and emission wavelength, full width at half maximum (FWHM), and crystalline size of the resulting CdS quantum dots (QDs) can be conveniently tuned. The quantum yield of the as-prepared QDs at 240 degrees C for 30 min can be up to 33%. Compared with the traditional hot-injection approach, QDs synthesized by microwave heating are more efficient and the shortening of the reaction time leads to a high reaction yield. The use of microwave 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 metal sulfide QDs.