Synthesis of high-quality and efficient quantum dots with inorganic surface passivation in a modified phosphine-free method

A green and modified mitre to synthesize high-quality luminescera quanium dots (QDs) with surface inorganic passivation is reported in this letter. Ordinary metal oxide (CdO, ZnO), pellets of Se and S were used to prepare nanocrystals in paraffin liquid. The luminescent properties were investigated by UV-vis absorption and photoluminescent spectra. The photoluminesence quantum yield (PL QY) of as prepared passivated QDs reached as high as 68% and the full width at half maximum (FWHM) stayed at 28 rim from the PL spectra. Fast Fourier transform algorithm (FFT) on high-resolution lattice fringes confirmed that the QDs was successfully coated and alloyed by the inorganic shell. Additionally, it was found that the net atmosphere plays an important role to obtain higher quality QDs in paraffin liquid. (C) 2014 Elsevier B.V. All rights reserved.