Influence of zinc ion concentration on structure, morphology and optical properties of spray deposited ZnO thin films

Sarika Vishvnbath Jadhav,Limbraj Sopan Ravangave

doi:10.11591/ijaas.v10.i3.pp198-204

Sarika Vishvnbath Jadhav, Limbraj Sopan Ravangave

Open Access

https://doi.org/10.11591/ijaas.v10.i3.pp198-204

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Abstract

<p>Zinc Oxide (ZnO) thin films were deposited for five different molarity (M) of Zinc acetate hydrated (0.075, 0.1, 0.125, 0.15, 0.175 M) using simple spray technique to study the effect of zinc ion concentration on structure, morphology and optical properties. The XRD patterns of deposited ZnO thin films show hexagonal crystal structure with wurtzite symmetry. The effect of molarity on morphology was studied using scanning electron microscopy (SEM). The elemental analysis was studied by using energy dispersive X-ray analysis (EDX). The optical absorption was recorded by using systronics double beam spectrophotometer (2201). Crystallite size estimated from XRD data was in nanometre (nm) range; however, films deposited for 0.15 M zinc acetate show maximum crystallite size (66 nm) as compared to other samples. All the films show low absorption in wide range (340-999 nm) of electromagnetic spectrum. However, ZnO film deposited for 0.15 zinc acetate hydrated shows maximum blue shifting of absorption edge and higher band gap (3.8 eV) as compared to other samples.</p>

Highlights

Zinc oxide (ZnO) is a hexagonal crystal system, exhibit stable wurtzite crystal structure in which the oxygen ions are surrounded by four zinc ions forming tetrahedron
The crystallity of ZnO thin films was increased on increasing molarity of zinc acetate hydrated
ZnO thin films were deposited by using chemical spray pyrolysis technique by varying molarity of zinc acetate hydrated

Summary

Introduction

Zinc oxide (ZnO) is a hexagonal crystal system, exhibit stable wurtzite crystal structure in which the oxygen ions are surrounded by four zinc ions forming tetrahedron. The direct optical band gap of ZnO was in the range 3⋅2 to 3.37 elecron volt (eV), exhibit higher transmittance in the visible region of electromagnetic spectrum and large exciton binding energy of 60 meV due to these reasons, ZnO materials have numerous applications in solar cells and in optoelectronic devices as an optical wave guide [2], [3]. ZnO thin films in pure and doped forms have been used as photocatalytic activators, chemical and biological sensors [4], [5], besides these ZnO nanoparticles have been used as biomedical materials for synthesis of antiseptic and antibacterial creams, lotions [6]. Chemical spray pyrolysis (CSP) is an innovative technique suitable for large area thin-films deposition and very economic [12]

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