Study of Structural and Optical Properties of Undoped and Cd Doped SnO&lt;sub&gt;2&lt;/sub&gt; Thin Films Prepared by Sol-Gel Dip Coating Technique

M Khechba,A Bouabellou,S Touati,F Hanini

doi:10.19026/rjaset.14.5143

Abstract

In this study, we report the study of the surface morphology, the structural and optical proprieties of transparent cadmium doped tin dioxide (Cd:SnO<sub>2</sub>) thin films deposited on glass and Si(100) substrates by Sol Gel Dip Coating (SGDC) technique. The analysis was carried out using Grazing Incidence X-Ray Diffraction (GIXRD), Atomic Force Microscopy (AFM), UV-Vis spectrophotometry and Spectroscopic Ellipsometry (SE). The X-ray diffraction reveals that all films deposited on Si(100) substrate have tetragonal crystalline structure with preferential orientation along (310) plane, but an amorphous structure is obtained for all the films prepared on glass substrate. The surface roughness, observed by means of AFM varies from 19 to 4 nm. The optical measurements show that the deposited Cd:SnO<sub>2</sub> films have a high transparency (~86%) in the visible spectrum and a band gap energy decreasing from 3.60 eV to 3.31 eV with increasing Cd concentration. The obtained values of the refractive index of the films are ranging between 1.559 and 1.613.

Highlights

Transparent Conducting Oxide (TCO) materials have a greater importance due to the large variety of their applications such as electrochromic devices (Kuo et al, 2012), solar cells (Kim et al, 2010), optoelectronics devices (Ramamoorthy et al, 2006)
The aim of this study is to study the structural and optical properties of cadmium doped SnO2 films deposited by Sol Gel Dip Coating (SGDC) technique onto silicon and glass substrates with different cadmium doped tin dioxide (Cd) doping concentrations
The effect of Cd doping on the physical properties of the fabricated SnO2 thin films is elucidate

Summary

Introduction

Transparent Conducting Oxide (TCO) materials have a greater importance due to the large variety of their applications such as electrochromic devices (Kuo et al, 2012), solar cells (Kim et al, 2010), optoelectronics devices (Ramamoorthy et al, 2006). SnO2 which is non toxic and abundant material in nature, is characterized by a wide band gap (Eg = 3.6 eV), a high electrical conductivity, a high transmittance in the ultraviolet–visible region and a high infrared (IR) reflectance (Ginley and Bright, 2000; Minami, 2000) Additive elements such as Cu (Vasiliev et al, 1998; Shuping et al, 2008; Patil and Patil, 2006; Yamazoe et al, 1996; Jin et al, 2006), Pd (Shimizu et al, 1998; Shen et al, 2009; Manjula et al, 2009; Pavelko et al, 2009; Cioffi et al, 2006), In Durrani et al (2005) and Shukla et al (2007) and rare earth elements (Samotaev et al, 2007) are used to improve the sensor response, selectivity and surface modification. The effect of Cd doping on the physical properties of the fabricated SnO2 thin films is elucidate

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Results