Synthesis of ZnSe nanocrystals (NCs) using a rapid microwave irradiation method and investigation of the effect of copper (Cu) doping on the optical properties

ZnSe nanocrystals (NCs) were synthesized using a microwave activated method. Synthesized NCs were characterized by means of X-ray diffraction (XRD), UV-visible (UV-vis) optical spectroscopy and photoluminescence (PL). XRD analysis demonstrated cubic zinc blende NCs. TEM image indicated round shape NCs and most of the particles had diameters of about 3 nm. Band gap of the NCs was obtained about 3.15 eV and PL spectra indicates a broad emission with two peaks located about 415 and 500 nm related to band edge and trap state respectively. For ZnSe:Cu NCs, PL intensity of band gap emission of ZnSe NCs at 415 nm decreased gradually with the increase in the concentration of Cu dopant ions and for precursor ratio of Cu:Zn 1% band gap emission at 415 nm disappeared completely. At the same conditions, PL QY was obtained about 2% and 8% for ZnSe and ZnSe:Cu (1%) NCs, respectively.