L’effet de la température du substrat et de la molarité sur les propriétés des couches minces de sulfure de zinc déposées par spray ultrasonique

Abstract

In the present work, we have deposited a set of ZnS thin films on the glass substrate. The objective of this study is to investigate the effect of the molarity and substrate temperature on the properties of this material. These layers were characterized by various techniques such as the: structural, morphological, optical and the electrical characterization. Therefore we have divided this study in two parts. In the first part; we have varied the substrate temperature from 300°C to 500 °C, with fixing the rest of the parameters, such as solution molarity and the time of deposition (0.1mol/l, 10min). But in the second part we have Change the molarity of the solution from 0.05mol/l to 0.3mol/l, with fixing the rest of the factors, such as substrate temperature and duration of deposition (450°C, 10min) The structural characterization of the films by X-ray diffraction has permit us to deduce that the films are amorphous at the temperatures lower then 350°C and poly crystalline at the temperatures higher than this value. Also through the X-ray spectra, we have calculated the grain size and deformation. And by scanning electron microscope we have studied the nature of the surface. The optical characterization of deposited films was carried out using UV-Vis spectrometry in the spectral range 300-850 nm. The analysis of the transmittance spectra allows us to deduce the optical band gaps and the urbach energy. The electrical characterization obtained by Hall effect and two points, allow us to deduce that we have obtained an insulating layer.