Facile Synthesis and Characterization of CdSe/ZnSe Core/Shell and ZnxCd1−xSe Alloy Quantum Dots via Non-organometallic Route

Abstract

Hexadecylamine (HDA) capped CdSe/ZnSe core/shell and ZnxCd1−xSe alloy quantum dots (QDs) have been synthesized successfully via a non-organometallic, hot injection method. The optical, structural and morphological properties of the as-synthesized QDs were determined by using, UV–visible (UV–Vis) and photoluminescence spectroscopy, X-ray diffraction and transmission electron microscopy (TEM). The effect of reaction time and temperature on the core/shell and alloy formation were investigated in detail. The addition of ZnSe precursor to the pre-synthesized HDA capped CdSe QDs at 230 °C produced core/shell CdSe/ZnSe QDs whereas at 250 °C an alloy QDs were obtained initially which later transformed to core/shell structure with time. On the other hand, the immediate addition of ZnSe precursor to the hot CdSe-precursor solution in HDA at 230 °C resulted in HDA capped ZnxCd1−xSe alloy QDs. The optical and structural characterisation shows that the as-synthesised core–shell and alloy QDs are of high quality. This method is simple, and fast for the preparation of core/shell and alloy binary QDs and will encourage their synthesis for various industrial applications.