Investigations des propriétés photoluminescentes des nanoparticules de ZnS dopées

Abstract

ZnS nanocrystals are promising candidates for the development of non-toxic, high-performance nano luminophores. Thanks to their size and high absorption, these nano-luminophores allow the exploitation of nano-optical effects that can increase their emission efficiency. And allowed the most used methods to improve these properties and well it is doping. Therefore, we decided to study three series with different dopants (Ca2+, Dy3+, Sm3+, Ag+, Co2+) of different families of materials. And in order to better exploit this method we have also made double doping. This paper first presents ZnS and most of these interest properties and applications. Then we describe the method used for the synthesis which is hydrothermal while explaining the different parameters studied to optimize the procedure. The NPs synthesized were characterized by ray diffraction (DRX), structural analysis as a function of temperature under controlled atmosphere (HTK), RAMAN spectroscopy, as well as scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in order to determine the morphology. The optical study of the different NPs was done using excitation photoluminescence (PLE), emission photoluminescence (PL), lifetime (LT) and quantum yield (QY). At the finals we were able depending on the doping not only to modify the crystalline structure and these parameters but also to make a phase change and move to a two-phase structure. While the luminescent study has allowed us to see the improvement of the PL as well as the LT depending on the dopant but also other effects that have been explained and details. The study was carried out in order to deepen the understanding of the mechanisms responsible for such effects