Growth and Correlation of the Physical and Structural Properties of Hexagonal Nanocrystalline Nickel Oxide Thin Films with Film Thickness

Abstract

This study investigated nonstoichiometric nickel oxide thin films prepared via the DC-sputtering technique at different film thicknesses. The prepared films were characterized by a surface profiler for thickness measurement, X-ray diffraction (XRD) for film nature, atomic force microscopy (AFM) for film morphology and roughness, UV-visible-near infrared (UV-vis.-NIR) spectroscopy for optical transmittance spectra of the films, and the photoluminescence (PL) spectra of the prepared films were obtained. The measured film thickness increased from 150 to 503 nm as the deposition time increased. XRD detected the trigonal crystal system of NiO0.96. The crystallite sizes were mainly grown through (101) and (110) characteristic planes. NiO0.96 films have a spherical particle shape and their sizes decreases as the film thickness increased. The optical band gap values decrease from 3.817 to 3.663 eV when the film thickness increases. The refractive index was estimated from the Moss relation, while the high-frequency dielectric constant and the static dielectric constant were deduced from the empirical Adachi formula. The photoluminescence behavior of the studied films confirmed the photogeneration of an electron-hole in nickel and oxygen vacancies. Hence, this study confirms the presence of nickel oxide lattice in the hexagonal structure containing the defects originated from the nickel vacancies or the excess of oxygen.

A novel high performance photodetection based on axial NiO/β-Ga2O3 p-n junction heterostructure nanowires array

“…Moreover, a UV emission was observed for NiO/β-Ga 2 O 3 HS NW at 372 nm, and a small hump observed for NiO/β-Ga 2 O 3 HS TF at same energy with less intensity than axial HS NW. This peak at 372 nm can be ascribed to the exciton-exciton scattering corresponding to the NiO material [43]. Both the peaks at 340 nm (3.64 eV) and 330 nm (3.75 eV) can be ascribed due to the near band emission (NBE) for β-Ga 2 O 3 material in case of HS TF and axial HS NW respectively [44].…”

Effect of Cuprous Oxide Nanocubes and Antimony Nanorods on the Performance of Silicon Nanowire-Based Quasi-Solid-State Solar Cell

“…This can be achieved by lowering the electrodeposition time of the NiO film. Hammad et al prepared NiO on the glass substrates/Si wafer by DC-sputtering method . They showed that the optical band gap of NiO films decreases as the film thickness increases; the thin film showed higher and broader UV–visible–NIR optical transmittance compared to the thick films.…”

“…Hammad et al prepared NiO on the glass substrates/Si wafer by DC-sputtering method. 46 They showed that the optical band gap of NiO films decreases as the film thickness increases; the thin film showed higher and broader UV–visible–NIR optical transmittance compared to the thick films. Chen et al also reported the preparation of NiO films by DC magnetron sputtering.…”