Impact of Aluminium on ZnO Thin Films for Antimicrobial Activity

Ba Anandh,R Sakthivel,S Subramani,A.T Rajamanickam,A Shankar Ganesh

doi:10.14233/ajchem.2021.23342

Abstract

Thin films of pure zinc oxide (ZnO) and aluminium (Al) doped ZnO were deposited by two step SILAR technique. Pure and Al (1%, 3%, 5%) doped ZnO thin film’s structural, morphology and optical properties were analyzed. Diffraction peaks of all the samples were indexed to hexagonal Wurtizite structure. The crystallite size, lattice parameters, dislocation density and microstrain were calculated for the prepared thin films. Morphology study using FESEM shows spherical shaped structure of pure ZnO and hexagonal faced rod like structure for Al doped ZnO thin films. The UV-vis absorption spectrum for the thin films was also studied. There is decrease in bandgap as the Al doping ratio increases from 1% to 5%. Photoluminescence studies confirmed that oxygen ion vacancy and interstitial Zn+ ion were present. The maximum zone of inhibition was studied against the Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria by agar diffusion method. Significant antimicrobial results were seen in pure and Al doped ZnO. Aluminium doped ZnO shows more antimicrobial activity over pure ZnO.

Highlights

Zinc oxide (ZnO) is a semiconductor with possible applications in different fields because of its significant physical properties
Thin films of pure Zinc Oxide (ZnO) and Aluminium (Al) doped ZnO were deposited by two step Successive Ionic Layer Adsorption and Reaction (SILAR) technique
ZnO is more stable in the hexagonal wurtzite phase rather than other phases at room temperature

Summary

Introduction

Zinc oxide (ZnO) is a semiconductor with possible applications in different fields because of its significant physical properties. It is an II-VI semiconductor which crystallizes in rock salt, wurtzite and rock salt forms. ZnO is more stable in the hexagonal wurtzite phase rather than other phases at room temperature. Studies on thin films have improved several novelparts of analysis which depends on exclusive characteristic and structures [1]. ZnO has very good chemical stability, excellent thermal stability, high exciting binding energy (60meV) and wide bandgap (3.37eV) at room temperature. ZnO thin films have good electrical and optical properties, very high electrical resistivity, low cost and are non-toxic [2]

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