Influence of Co concentration on properties of NiO film by sparking under uniform magnetic field

Abstract

Nickel oxide (NiO) films cover numerous electronic applications, including transparent conducting oxides and hole transport layer, because of its high transparency and wide band gap. A sparking discharge is a new and unique method for the deposition of NiO films due to non-complex operation and non-requirement of a vacuum atmosphere. Unfortunately, NiO films by the sparking method display a porous surface with inferior crystallinity. By assisting a uniform magnetic field in the sparking method, the porous and the crystallinity of NiO are improved. However, electrical properties of the NiO films deposited by this strategy are poor. In order to improve the electrical properties of NiO, a substitutional of Ni ions by Co ions is considered. In this study, we report an influence of Co concentration on properties of NiO films by sparking under a uniform magnetic field. Our results indicate that an increase in Co concentration to 0.1 M improves the crystallinity and increases a carrier concentration of NiO, resulting in a reduction of the resistivity. This consequence is in agreement with the increase in a number of higher-valence Ni3+ because of the Co2+ substituted Ni2+. Based on our research, Co-NiO film is promising materials for a transparent conductor.

Improving the properties of Fe2O3 by a sparking method under a uniform magnetic field for a high-performance humidity sensor

“…Interestingly, this result was not in accordance with our previous work, which indicated that an increase in the magnetic eld reduced the porosity of the NiO lm. 14,15 The reason for this result was the earlier oxidation of Fe particles without annealing, which resulted in misalignment of the particles. 12 The crystal structure of Fe 2 O 3 lms analyzed by XRD is displayed in Fig.…”

“…Published by the Royal Society of Chemistry collect more particles. To reveal the inuence of the magnetic eld on the bandgap (E g ) of Fe 2 O 3 , we used Tauc's relationship, as determined by the following equation: 14,15 (ahn) ¼ A(hn À E g ) n…”

“…1 ). 15 Fe wires (99.98% purity; Advent Research Materials) were deposited onto the glass substrate for 30 min. Then, films were annealed at 450 °C under ambient air for 2 h.…”

“…12,13 Previously, we showed that an increase in the magnitude of a uniform magnetic eld reduces the porosity and improves the crystal structure as well as the electrical properties of a NiO lm. 14,15 Thus, a sparking method under a uniform magnetic eld could be employed to produce a Fe 2 O 3 lm and optimize its properties for humidity sensors.…”

Copper-Iron Oxide: A Highly Effective Photocatalyst Than TiO2 Prepared by One-Step Sparking Process

“…In this work, we aim to synthesize novel Cu-Fe oxides composite lms by a one-step sparking process. This process has been developed in our lab which can prepare small, uniform particles, high porous lms, and determine the composite ratio [18][19][20][21][22][23][24][25][26]. Moreover, the sparking process requires neither complicated steps nor special equipment, cheap, fast, and non-toxic.…”