Multi-injection Synthesis of CdSe Nanocrystals by Solution Process with Glycerol-Ethylene Glycol

Wurtzite CdSe nanocrystals were synthesized by a multi-injection solution chemical process with glycerol-ethylene glycol based solvent,sodium selenite and cadmium nitrate-tetrahydrate as precursors,ammonia as a chelating agent and hydrazine hydrate as a reducing agent.The crystal phase,morphologies and optical absorption of the as-prepared CdSe nanocrystals were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy and UV-Vis analysis,respectively.The relation between the light absorbance and reaction time for three reaction solutions with different hot injection styles was analyzed via the UV-Vis measurement at a wavelength of480 nm.The results show that the injection style in the multi-injection process has an effect on the nucleation and growth,crystal size,dispersing stability and optical band-gap energy of the nanocrystals.The mild injection style results in the formation of uniform and well-dispersive nanocrystals.