Effect of Precursor Concentration on Structural Optical and Electrical Properties of NiO Thin Films Prepared by Spray Pyrolysis

Rafia Barir,Boubaker Benhaoua,Rachid Gheriani,Toufik Sahraoui,Soufiane Benhamida,Achour Rahal

doi:10.1155/2017/5204639

Abstract

Undoped nickel oxide (NiO) thin films were deposited on 500°C heated glass substrates using spray pyrolysis method at (0.015–0.1 M) range of precursor. The latter was obtained by decomposition of nickel nitrate hexahydrate in double distilled water. Effect of precursor concentration on structural, optical, and electrical properties of NiO thin films was investigated. X-ray diffraction (XRD) shows the formation of NiO under cubic structure with single diffraction peak along(111)plane at2θ=37.24°. When precursor concentration reaches 0.1 M, an increment in NiO crystallite size over 37.04 nm was obtained indicating the product nano structure. SEM images reveal that beyond 0.04 M as precursor concentration the substrate becomes completely covered with NiO and thin films exhibit formation of nano agglomerations at the top of the sample surface. Ni-O bonds vibrations modes in the product of films were confirmed by FT-IR analysis. Transparency of the films ranged from 57 to 88% and band gap energy of the films decreases from 3.68 to 3.60 eV with increasing precursor concentration. Electrical properties of the elaborated NiO thin films were correlated to the precursor concentration.

Highlights

Transition metal oxides (TMOs) have attracted great attention in fundamental research field recently, because of their diverse physical properties, materials science, renewable energy, and microelectronics and nanotechnology fields applications [1,2,3,4]
It is seen from X-ray diffraction (XRD) patterns that only single peak appears at 2θ = 37.24∘, which is attributed to the (111) diffraction peak and clearly indicated that the nickel oxide (NiO) phase exists under its face centered cubic structure, which is in good agreement with Joint Committee on Powder Diffraction Standards (JCPDS card number 47-1049) [52]
Undoped nickel oxide (NiO) thin films were deposited on 500∘C heated glass substrates using spray pyrolysis method

Summary

Introduction

Transition metal oxides (TMOs) have attracted great attention in fundamental research field recently, because of their diverse physical properties, materials science, renewable energy, and microelectronics and nanotechnology fields applications [1,2,3,4]. They were used as light-emitting diodes (LEDs) [5], smart windows [6], and electrode material for Liion batteries [7]. NiO is a very important VIII–VI semiconductor having NaCl-type structure [10]. It was shown that NiO thin films exhibit weak resistivity which maybe is due to the creation of nickel vacancies and interstitial oxygen atoms in their structures [13, 14]

Methods

Results

Conclusion