Spray Pyrolysed Nanostructured Gold-Doped Tin Oxide (Auto) Thin Films

S.I Akinsola,A.B Alabi,O.A Babalola,A.A Ajayi,K.S Adedayo,D.B Olanrewaju

doi:10.4314/jasem.v25i4.12

Abstract

Nanostructured SnO2 thin films were grown by the chemical spray pyrolysis (CSP) method. Homemade spray pyrolysis technique is employed to prepare thin films. SnO2 is wide band gap semiconductor material whose film is deposited on glass substrate. A gold nanoparticle-doped tin oxide thin film (AuTO) was also prepared. UV-VIS (ultraviolet visible) spectroscopy and four-point probe analysis are done for optical and electrical analysis. UV-Visible absorption spectra show that the band gap of SnO2 thin film is 3.78 eV and 3.82 eV for AuTO. Band gap of SnO2 thin film can be tuned that it can be used in optical devices. The films have transmittance increases (to about 60%) and the absorbance decreases in the visible region of the electromagnetic spectrum. The electrical conductivity of the Tin Oxide is enhanced by functionalizing with the Gold nanoparticles. It is higher than that of the Tin oxide only; 0.77 x 10-2 (Ohm cm)-1 and 3.55 x 10-2 (Ohm cm)-1 for SnO2 and AuTO respectively. These properties reveal that Tin Oxide doped with gold can actually be a good material for a transparent conducting oxide to be used in photovoltaic fabrication and in electronics.

Highlights

Tin oxide is known as a wide band gap semiconductor, and it has only the tin atom that occupies the center of a surrounding core composed of six oxygen atoms placed approximately at the corners of a quasiregular octahedron, according to Patil, et al, (2012)
Tin oxide has been doped with gold nanoparticles and the obtained optical and electrical properties, especially as applicable for use in solar cell have been studied
The objective of this work is to study the effect of functionalizing SnO2 with gold nanoparticle on its application as a transparent conducting oxide, as alternative to the already existing Fluorine doped tin oxide (FTO) and ITO glass

Summary

Introduction

Tin oxide is known as a wide band gap semiconductor (energy band gap 3.6eV), and it has only the tin atom that occupies the center of a surrounding core composed of six oxygen atoms placed approximately at the corners of a quasiregular octahedron, according to Patil, et al, (2012). Hoang and Shankar, (2011) reported that a key advantage of tin oxide over other contemporary semiconductors like silicon or gallium arsenide is its chemical stability and being corrosion resistant. Fluorine doped tin oxide (FTO) exhibits good visible transparency as a result of its wide band-gap, while retaining a low electrical resistivity due to the high carrier concentration caused by the oxygen vacancies and the substitutional fluorine dopant. Unlike many other film deposition techniques, spray pyrolysis is a simple and relatively cost-effective method (especially when considering the cost of equipment). Much work has not been reported on doping tin oxide with gold vis-à-vis the effects on the electrical and optical properties of thin films. Tin oxide has been doped with gold nanoparticles ( the nomenclature AuTO) and the obtained optical and electrical properties, especially as applicable for use in solar cell have been studied. The objective of this work is to study the effect of functionalizing SnO2 with gold nanoparticle on its application as a transparent conducting oxide, as alternative to the already existing FTO and ITO glass

Objectives

Methods

Results