Synthesis and study of optical properties of ZnTe/ZnSe core/shell and ZnTe/ZnSe/ZnS core/shell/shell semiconductor nanocrystals

Abstract

ZnTe/ZnSe core/shell and ZnTe/ZnSe/ZnS core/shell/shell semiconductor nanocrystals (NCs) have been successfully fabricated by wet chemicals in an ODE solvent. The crystal structure, phonon characteristics and optical properties of the NCs were investigated using X-ray diffraction (XRD), Raman scattering (RS), photoluminescence (PL) spectroscopy, PL decay time, and absorption spectrum (Abs). The growth of ZnSe shell on ZnTe core and ZnS shell on ZnTe/ZnSe core/shell is demonstrated through XRD and RS. Observation results from XRD diagram show that all fabricated NCs are crystallized in cubic structure. The ZnS shell significantly enhanced the quantum yield (QY) of the ZnTe/ZnSe NCs. The effect of excitation power on the emission properties of ZnTe, ZnTe/ZnSe and ZnTe/ZnSe/ZnS NCs has been studied and explained in detail.