A.Kabir
Skikda University, Algeria
Title: Structural and morphological characterization of tin oxide films prepared by the RGTO method
Biography
Biography: A.Kabir
Abstract
Tin oxide (SnO2) is a largely used material in different domains such as nanocrystalline photovoltaic cells and gas sensing. In this work, this material was deposited by the RGTO method (Rheotaxial Growth and Thermal Oxidation). This technique, which consists on the thermal oxidation of the Sn films deposited onto heated glass substrate at a temperature close to tin melting point (232°C), allows preparing high porosity tin oxide films. This films type is very suitable for the gas sensing. The films structural and morphological properties pre and post oxidation were studied using the x-ray diffraction (XRD) and the scanning electron microscopy (SEM) respectively. XRD patterns showed a polycrystalline structure of the cassiterite phase of SnO2. The grain size increased as a function of the oxidation time and tended to saturate. This grain size evolution was confronted to existing grain growth models in order to understand the growth mechanism. From SEM images, the as deposited Sn film was formed of difference diameter spherical agglomerations. As a function of the oxidation time, these spherical agglomerations size increased and their shape changed due to the introduction of oxygen ions. The deformed spheres started to interconnect by forming bridges between them. These bridges induced the decrease of the electrical resistivity