Phosphine-Free Synthesis of High Quality CdSe Nanocrystals and Their Optical Properties

Abstract

High quality zinc blende CdSe nanocrystals were successfully synthesized using an environmental friendly method.Pre-synthesized cadmium decanoate was used as the Cd precursor and selenium powder dissolved in octadecene was used as the Se precursor.The use of expensive and toxic tributylphosphine or trioctylphosphine was thus avoided.The properties and structures of the as-synthesized CdSe nanocrystals were characterized by absorption spectroscopy,photoluminescence (PL) spectroscopy,X-ray diffraction (XRD),and transmission electron microscopy (TEM).The PL emission peak of the as-synthesized CdSe nanocrystals could be easily tuned from 470 to 630 nm using different reaction times.The quality of the crystals was high and this was confirmed by their high quantum yields (exceeding 60% at 535 nm) and their narrow size-distributions with full width at half maximum values between 24 and 30 nm.