Zhang X.,Southwest University for Nationalities |
Zhang X.,Chengdu Chemtide T echnology Co. |
Xu M.,Southwest University for Nationalities |
Yu C.,Chengdu Chemtide T echnology Co. |
And 3 more authors.
Optoelectronics and Advanced Materials, Rapid Communications | Year: 2015
High-quality ZnSe/ZnS core/shell nanocrystals were synthesized by a convenient aqueous phase method, achieving epitaxial growth at a very low temperature of 90℃. The nature of the ZnS shells grown on the surfaces of ZnSe core nanocrystals (average size, 4~5 nm) was determined by X-ray diffraction (XRD), UV -Vis spectrophotometry, photoluminescence (PL) measurements, high-resolution transmission electron microscopy (HR-TEM), and Fourier transform infrared spectroscopy (FT -IR). The PL intensity of ZnSe/ZnS quantum dots (QDs) first increased and then decreased with increasing pH value. The strongest PL intensity occurs at the pH value of ~10.5. The strongest PL peak was centered at 400 nm (FWHM ~22 nm). The mechanism of the observed optical properties is discussed. © 2015, National Institute of Optoelectronics. All rights reserved. Source