Core–shell ZnSe–CdSe quantum dots: a facile approach via decomposition of cyclohexeno-1,2,3-selenadiazole

Abstract

For the first time ever cyclohexeno-1,2,3-selenadiazole (SDZ) has been employed for the synthesis of core–shell ZnSe–CdSe quantum dots thus promoting an eco-friendly and reasonably less toxic synthesis method for such quantum dot hetero-structures. The synthesized dark-red colored core–shell structures were characterized by UV-Visible and photoluminescence (PL) spectroscopy to examine their band-gap. The absorption and emission spectra also showed gradual red-shifts in wavelength with respect to zinc selenide (core). Also, the band-gap of such core–shell quantum dots can be tuned by varying the shell layer thickness and/or particle size. The findings from the XRD analysis, near-to-homogenous particle size distribution, formation of a decent nano-crystalline product and a good agreement with Vegard's law, signify that the present synthesis approach could be highly effective for the precise tailoring of core–shell QDs.