Luminescence properties of ZnS-ZnO nanocomposites synthesized by solvothermal method

Abstract

In the past decade, II-VI semiconductor nanoparticles attract much attention because of their size-dependent (and thus tunable) photo- and electro- luminescence properties and promising applications in optoelectronics. In this work we report on the synthesis of ZnS-ZnO semiconductor nanocomposites by noval and simple solvothermal method. The prepared nancomposites of different ratios were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), UV-VIS absorption, Photoluminescence (PL) spectra and Photoconductivity (PC). X-ray diffraction (XRD) study confirmed the formation of multiphase of ZnS- ZnO nanocrystals . The calculated grain sizes using the Scherrer formula were found to be less than 4.5nm match with the SEM results. The UV-VIS absorption spectra show that the absorption edges of all nanocrystals fall within 310 to 350nm which explains a blue shift in wavelength corresponding to bulk.. Photoluminescence spectra of the nanocomposites exhibit five prominent peaks in the PL spectra. The peaks are observed at around 408, 446, 486, 490 and 530nm.