Preparation and characterization of nanostructured nickel oxide thin films by spray pyrolysis

Abstract

Transparent crystalline nanostructured nickel oxide (NiO) thin films were prepared using a simple spray pyrolysis technique from hydrated nickel chloride salt solution (NiCl 2 Á6H 2 O) onto glass and silicon (n-type) substrates at different temperatures (280, 320, 360, and 400°C) and with different solution concentrations (0.025, 0.05, 0.075, and 0.1 M). Structural and morphological properties of the grown NiO films were studied using X-ray diffraction (XRD) and atomic force microscope. Optical properties and chemical analysis of the films were characterized by UV-visible absorption spectra and Fourier transform infrared spectroscopy, respectively. The XRD result showed that the deposited film has an amorphous structure when deposited at temperature of T s = 280°C and concentration of 0.025 M. At higher temperatures (T s = 320, 360, 400°C) and solution concentrations (0.05, 0.075, 0.1 M), the deposited films have cubic polycrystalline structure formed with preferred orientation along (111) plane. The band gap of NiO film increases from 3.4 to 3.8 eV as the molarity decreased from 0.1 to 0.05 M.

Effect of Co Doping on Structural and Optical Properties of NiO Thin Films Prepared by Chemical Spray Pyrolysis Method

“…The undoped NiO sample has highest average grain size, average roughness and RMS roughness of the film surface. The increase in the crystallite size may be caused by columnar grain growth in the structure which is in agreement with other studies [11]. …”

“…The strongest peak occurs at 2θ~37° which is referred to (111) plane. The positions of the peaks and the presence of more than one diffraction peak lead to the conclusion that the films are polycrystalline in nature with a cubic crystalline structure, which is in agreement with other reports [10,11].…”

Effect of Substrate Temperature on the Optical and Electrical Properties of Nitrogen-Doped NiO Thin Films

“…Therefore, it is crucial to modulate the optical and electrical properties of NiO thin films to exploit its applications. There are many methods to fabricate NiO thin films, such as chemical vapor deposition [4], facile sol-gel synthesis [5], magnetron sputtering [6], spray pyrolysis [7], and pulsed laser deposition [8]. Among them, magnetron sputtering is the most used, with the advantages of high quality, good adhesion, low growth temperature, and high efficiency [9].…”

Farbication of UV photodetector from nickel oxide nanoparticles deposited on silicon substrate by closed-field unbalanced dual magnetron sputtering techniques

“…Figure 2 shows the results of AFM test for the NiO samples prepared at inter-electrode distance of 4 cm, where significantly homogeneous distribution of the NiO nanoparticles was produced with average roughness of 1.24 nm and root mean square value of 1.49 nm. The increase of the crystallite size may be caused by columnar grain growth in the structure (Ismail et al 2013). The high ratio of surface area to volume of the prepared NiO nanoparticles may present an advantage to use such surfaces in photonic and optoelectronic devices employing NiO nanostructures.…”